/* * USB hub driver. * * (C) Copyright 1999 Linus Torvalds * (C) Copyright 1999 Johannes Erdfelt * (C) Copyright 1999 Gregory P. Smith * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au) * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "usb.h" /* if we are in debug mode, always announce new devices */ #ifdef DEBUG #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES #define CONFIG_USB_ANNOUNCE_NEW_DEVICES #endif #endif struct usb_hub { struct device *intfdev; /* the "interface" device */ struct usb_device *hdev; struct kref kref; struct urb *urb; /* for interrupt polling pipe */ /* buffer for urb ... with extra space in case of babble */ char (*buffer)[8]; union { struct usb_hub_status hub; struct usb_port_status port; } *status; /* buffer for status reports */ struct mutex status_mutex; /* for the status buffer */ int error; /* last reported error */ int nerrors; /* track consecutive errors */ struct list_head event_list; /* hubs w/data or errs ready */ unsigned long event_bits[1]; /* status change bitmask */ unsigned long change_bits[1]; /* ports with logical connect status change */ unsigned long busy_bits[1]; /* ports being reset or resumed */ unsigned long removed_bits[1]; /* ports with a "removed" device present */ #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */ #error event_bits[] is too short! #endif struct usb_hub_descriptor *descriptor; /* class descriptor */ struct usb_tt tt; /* Transaction Translator */ unsigned mA_per_port; /* current for each child */ unsigned limited_power:1; unsigned quiescing:1; unsigned disconnected:1; unsigned has_indicators:1; u8 indicator[USB_MAXCHILDREN]; struct delayed_work leds; struct delayed_work init_work; void **port_owners; }; static inline int hub_is_superspeed(struct usb_device *hdev) { return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS); } /* Protect struct usb_device->state and ->children members * Note: Both are also protected by ->dev.sem, except that ->state can * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */ static DEFINE_SPINLOCK(device_state_lock); /* khubd's worklist and its lock */ static DEFINE_SPINLOCK(hub_event_lock); static LIST_HEAD(hub_event_list); /* List of hubs needing servicing */ /* Wakes up khubd */ static DECLARE_WAIT_QUEUE_HEAD(khubd_wait); static struct task_struct *khubd_task; /* cycle leds on hubs that aren't blinking for attention */ static bool blinkenlights = 0; module_param (blinkenlights, bool, S_IRUGO); MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs"); /* * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about * 10 seconds to send reply for the initial 64-byte descriptor request. */ /* define initial 64-byte descriptor request timeout in milliseconds */ static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT; module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(initial_descriptor_timeout, "initial 64-byte descriptor request timeout in milliseconds " "(default 5000 - 5.0 seconds)"); /* * As of 2.6.10 we introduce a new USB device initialization scheme which * closely resembles the way Windows works. Hopefully it will be compatible * with a wider range of devices than the old scheme. However some previously * working devices may start giving rise to "device not accepting address" * errors; if that happens the user can try the old scheme by adjusting the * following module parameters. * * For maximum flexibility there are two boolean parameters to control the * hub driver's behavior. On the first initialization attempt, if the * "old_scheme_first" parameter is set then the old scheme will be used, * otherwise the new scheme is used. If that fails and "use_both_schemes" * is set, then the driver will make another attempt, using the other scheme. */ static bool old_scheme_first = 0; module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(old_scheme_first, "start with the old device initialization scheme"); static bool use_both_schemes = 1; module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(use_both_schemes, "try the other device initialization scheme if the " "first one fails"); /* Mutual exclusion for EHCI CF initialization. This interferes with * port reset on some companion controllers. */ DECLARE_RWSEM(ehci_cf_port_reset_rwsem); EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem); #define HUB_DEBOUNCE_TIMEOUT 1500 #define HUB_DEBOUNCE_STEP 25 #define HUB_DEBOUNCE_STABLE 100 static int usb_reset_and_verify_device(struct usb_device *udev); static inline char *portspeed(struct usb_hub *hub, int portstatus) { if (hub_is_superspeed(hub->hdev)) return "5.0 Gb/s"; if (portstatus & USB_PORT_STAT_HIGH_SPEED) return "480 Mb/s"; else if (portstatus & USB_PORT_STAT_LOW_SPEED) return "1.5 Mb/s"; else return "12 Mb/s"; } /* Note that hdev or one of its children must be locked! */ static struct usb_hub *hdev_to_hub(struct usb_device *hdev) { if (!hdev || !hdev->actconfig) return NULL; return usb_get_intfdata(hdev->actconfig->interface[0]); } /* USB 2.0 spec Section 11.24.4.5 */ static int get_hub_descriptor(struct usb_device *hdev, void *data) { int i, ret, size; unsigned dtype; if (hub_is_superspeed(hdev)) { dtype = USB_DT_SS_HUB; size = USB_DT_SS_HUB_SIZE; } else { dtype = USB_DT_HUB; size = sizeof(struct usb_hub_descriptor); } for (i = 0; i < 3; i++) { ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB, dtype << 8, 0, data, size, USB_CTRL_GET_TIMEOUT); if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2)) return ret; } return -EINVAL; } /* * USB 2.0 spec Section 11.24.2.1 */ static int clear_hub_feature(struct usb_device *hdev, int feature) { return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000); } /* * USB 2.0 spec Section 11.24.2.2 */ static int clear_port_feature(struct usb_device *hdev, int port1, int feature) { return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1, NULL, 0, 1000); } /* * USB 2.0 spec Section 11.24.2.13 */ static int set_port_feature(struct usb_device *hdev, int port1, int feature) { return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1, NULL, 0, 1000); } /* * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7 * for info about using port indicators */ static void set_port_led( struct usb_hub *hub, int port1, int selector ) { int status = set_port_feature(hub->hdev, (selector << 8) | port1, USB_PORT_FEAT_INDICATOR); if (status < 0) dev_dbg (hub->intfdev, "port %d indicator %s status %d\n", port1, ({ char *s; switch (selector) { case HUB_LED_AMBER: s = "amber"; break; case HUB_LED_GREEN: s = "green"; break; case HUB_LED_OFF: s = "off"; break; case HUB_LED_AUTO: s = "auto"; break; default: s = "??"; break; }; s; }), status); } #define LED_CYCLE_PERIOD ((2*HZ)/3) static void led_work (struct work_struct *work) { struct usb_hub *hub = container_of(work, struct usb_hub, leds.work); struct usb_device *hdev = hub->hdev; unsigned i; unsigned changed = 0; int cursor = -1; if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing) return; for (i = 0; i < hub->descriptor->bNbrPorts; i++) { unsigned selector, mode; /* 30%-50% duty cycle */ switch (hub->indicator[i]) { /* cycle marker */ case INDICATOR_CYCLE: cursor = i; selector = HUB_LED_AUTO; mode = INDICATOR_AUTO; break; /* blinking green = sw attention */ case INDICATOR_GREEN_BLINK: selector = HUB_LED_GREEN; mode = INDICATOR_GREEN_BLINK_OFF; break; case INDICATOR_GREEN_BLINK_OFF: selector = HUB_LED_OFF; mode = INDICATOR_GREEN_BLINK; break; /* blinking amber = hw attention */ case INDICATOR_AMBER_BLINK: selector = HUB_LED_AMBER; mode = INDICATOR_AMBER_BLINK_OFF; break; case INDICATOR_AMBER_BLINK_OFF: selector = HUB_LED_OFF; mode = INDICATOR_AMBER_BLINK; break; /* blink green/amber = reserved */ case INDICATOR_ALT_BLINK: selector = HUB_LED_GREEN; mode = INDICATOR_ALT_BLINK_OFF; break; case INDICATOR_ALT_BLINK_OFF: selector = HUB_LED_AMBER; mode = INDICATOR_ALT_BLINK; break; default: continue; } if (selector != HUB_LED_AUTO) changed = 1; set_port_led(hub, i + 1, selector); hub->indicator[i] = mode; } if (!changed && blinkenlights) { cursor++; cursor %= hub->descriptor->bNbrPorts; set_port_led(hub, cursor + 1, HUB_LED_GREEN); hub->indicator[cursor] = INDICATOR_CYCLE; changed++; } if (changed) schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD); } /* use a short timeout for hub/port status fetches */ #define USB_STS_TIMEOUT 1000 #define USB_STS_RETRIES 5 /* * USB 2.0 spec Section 11.24.2.6 */ static int get_hub_status(struct usb_device *hdev, struct usb_hub_status *data) { int i, status = -ETIMEDOUT; for (i = 0; i < USB_STS_RETRIES && (status == -ETIMEDOUT || status == -EPIPE); i++) { status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0, data, sizeof(*data), USB_STS_TIMEOUT); } return status; } /* * USB 2.0 spec Section 11.24.2.7 */ static int get_port_status(struct usb_device *hdev, int port1, struct usb_port_status *data) { int i, status = -ETIMEDOUT; for (i = 0; i < USB_STS_RETRIES && (status == -ETIMEDOUT || status == -EPIPE); i++) { status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1, data, sizeof(*data), USB_STS_TIMEOUT); } return status; } static int hub_port_status(struct usb_hub *hub, int port1, u16 *status, u16 *change) { int ret; mutex_lock(&hub->status_mutex); ret = get_port_status(hub->hdev, port1, &hub->status->port); if (ret < 4) { dev_err(hub->intfdev, "%s failed (err = %d)\n", __func__, ret); if (ret >= 0) ret = -EIO; } else { *status = le16_to_cpu(hub->status->port.wPortStatus); *change = le16_to_cpu(hub->status->port.wPortChange); ret = 0; } mutex_unlock(&hub->status_mutex); return ret; } static void kick_khubd(struct usb_hub *hub) { unsigned long flags; spin_lock_irqsave(&hub_event_lock, flags); if (!hub->disconnected && list_empty(&hub->event_list)) { list_add_tail(&hub->event_list, &hub_event_list); /* Suppress autosuspend until khubd runs */ usb_autopm_get_interface_no_resume( to_usb_interface(hub->intfdev)); wake_up(&khubd_wait); } spin_unlock_irqrestore(&hub_event_lock, flags); } void usb_kick_khubd(struct usb_device *hdev) { struct usb_hub *hub = hdev_to_hub(hdev); if (hub) kick_khubd(hub); } /* completion function, fires on port status changes and various faults */ static void hub_irq(struct urb *urb) { struct usb_hub *hub = urb->context; int status = urb->status; unsigned i; unsigned long bits; switch (status) { case -ENOENT: /* synchronous unlink */ case -ECONNRESET: /* async unlink */ case -ESHUTDOWN: /* hardware going away */ return; default: /* presumably an error */ /* Cause a hub reset after 10 consecutive errors */ dev_dbg (hub->intfdev, "transfer --> %d\n", status); if ((++hub->nerrors < 10) || hub->error) goto resubmit; hub->error = status; /* FALL THROUGH */ /* let khubd handle things */ case 0: /* we got data: port status changed */ bits = 0; for (i = 0; i < urb->actual_length; ++i) bits |= ((unsigned long) ((*hub->buffer)[i])) << (i*8); hub->event_bits[0] = bits; break; } hub->nerrors = 0; /* Something happened, let khubd figure it out */ kick_khubd(hub); resubmit: if (hub->quiescing) return; if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0 && status != -ENODEV && status != -EPERM) dev_err (hub->intfdev, "resubmit --> %d\n", status); } /* USB 2.0 spec Section 11.24.2.3 */ static inline int hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt) { return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo, tt, NULL, 0, 1000); } /* * enumeration blocks khubd for a long time. we use keventd instead, since * long blocking there is the exception, not the rule. accordingly, HCDs * talking to TTs must queue control transfers (not just bulk and iso), so * both can talk to the same hub concurrently. */ static void hub_tt_work(struct work_struct *work) { struct usb_hub *hub = container_of(work, struct usb_hub, tt.clear_work); unsigned long flags; int limit = 100; spin_lock_irqsave (&hub->tt.lock, flags); while (--limit && !list_empty (&hub->tt.clear_list)) { struct list_head *next; struct usb_tt_clear *clear; struct usb_device *hdev = hub->hdev; const struct hc_driver *drv; int status; next = hub->tt.clear_list.next; clear = list_entry (next, struct usb_tt_clear, clear_list); list_del (&clear->clear_list); /* drop lock so HCD can concurrently report other TT errors */ spin_unlock_irqrestore (&hub->tt.lock, flags); status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt); if (status) dev_err (&hdev->dev, "clear tt %d (%04x) error %d\n", clear->tt, clear->devinfo, status); /* Tell the HCD, even if the operation failed */ drv = clear->hcd->driver; if (drv->clear_tt_buffer_complete) (drv->clear_tt_buffer_complete)(clear->hcd, clear->ep); kfree(clear); spin_lock_irqsave(&hub->tt.lock, flags); } spin_unlock_irqrestore (&hub->tt.lock, flags); } /** * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub * @urb: an URB associated with the failed or incomplete split transaction * * High speed HCDs use this to tell the hub driver that some split control or * bulk transaction failed in a way that requires clearing internal state of * a transaction translator. This is normally detected (and reported) from * interrupt context. * * It may not be possible for that hub to handle additional full (or low) * speed transactions until that state is fully cleared out. */ int usb_hub_clear_tt_buffer(struct urb *urb) { struct usb_device *udev = urb->dev; int pipe = urb->pipe; struct usb_tt *tt = udev->tt; unsigned long flags; struct usb_tt_clear *clear; /* we've got to cope with an arbitrary number of pending TT clears, * since each TT has "at least two" buffers that can need it (and * there can be many TTs per hub). even if they're uncommon. */ if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) { dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n"); /* FIXME recover somehow ... RESET_TT? */ return -ENOMEM; } /* info that CLEAR_TT_BUFFER needs */ clear->tt = tt->multi ? udev->ttport : 1; clear->devinfo = usb_pipeendpoint (pipe); clear->devinfo |= udev->devnum << 4; clear->devinfo |= usb_pipecontrol (pipe) ? (USB_ENDPOINT_XFER_CONTROL << 11) : (USB_ENDPOINT_XFER_BULK << 11); if (usb_pipein (pipe)) clear->devinfo |= 1 << 15; /* info for completion callback */ clear->hcd = bus_to_hcd(udev->bus); clear->ep = urb->ep; /* tell keventd to clear state for this TT */ spin_lock_irqsave (&tt->lock, flags); list_add_tail (&clear->clear_list, &tt->clear_list); schedule_work(&tt->clear_work); spin_unlock_irqrestore (&tt->lock, flags); return 0; } EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer); /* If do_delay is false, return the number of milliseconds the caller * needs to delay. */ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay) { int port1; unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2; unsigned delay; u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics); /* Enable power on each port. Some hubs have reserved values * of LPSM (> 2) in their descriptors, even though they are * USB 2.0 hubs. Some hubs do not implement port-power switching * but only emulate it. In all cases, the ports won't work * unless we send these messages to the hub. */ if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2) dev_dbg(hub->intfdev, "enabling power on all ports\n"); else dev_dbg(hub->intfdev, "trying to enable port power on " "non-switchable hub\n"); for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++) set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER); /* Wait at least 100 msec for power to become stable */ delay = max(pgood_delay, (unsigned) 100); if (do_delay) msleep(delay); return delay; } static int hub_hub_status(struct usb_hub *hub, u16 *status, u16 *change) { int ret; mutex_lock(&hub->status_mutex); ret = get_hub_status(hub->hdev, &hub->status->hub); if (ret < 0) dev_err (hub->intfdev, "%s failed (err = %d)\n", __func__, ret); else { *status = le16_to_cpu(hub->status->hub.wHubStatus); *change = le16_to_cpu(hub->status->hub.wHubChange); ret = 0; } mutex_unlock(&hub->status_mutex); return ret; } static int hub_port_disable(struct usb_hub *hub, int port1, int set_state) { struct usb_device *hdev = hub->hdev; int ret = 0; if (hdev->children[port1-1] && set_state) usb_set_device_state(hdev->children[port1-1], USB_STATE_NOTATTACHED); if (!hub->error && !hub_is_superspeed(hub->hdev)) ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE); if (ret) dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n", port1, ret); return ret; } /* * Disable a port and mark a logical connect-change event, so that some * time later khubd will disconnect() any existing usb_device on the port * and will re-enumerate if there actually is a device attached. */ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1) { dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1); hub_port_disable(hub, port1, 1); /* FIXME let caller ask to power down the port: * - some devices won't enumerate without a VBUS power cycle * - SRP saves power that way * - ... new call, TBD ... * That's easy if this hub can switch power per-port, and * khubd reactivates the port later (timer, SRP, etc). * Powerdown must be optional, because of reset/DFU. */ set_bit(port1, hub->change_bits); kick_khubd(hub); } /** * usb_remove_device - disable a device's port on its parent hub * @udev: device to be disabled and removed * Context: @udev locked, must be able to sleep. * * After @udev's port has been disabled, khubd is notified and it will * see that the device has been disconnected. When the device is * physically unplugged and something is plugged in, the events will * be received and processed normally. */ int usb_remove_device(struct usb_device *udev) { struct usb_hub *hub; struct usb_interface *intf; if (!udev->parent) /* Can't remove a root hub */ return -EINVAL; hub = hdev_to_hub(udev->parent); intf = to_usb_interface(hub->intfdev); usb_autopm_get_interface(intf); set_bit(udev->portnum, hub->removed_bits); hub_port_logical_disconnect(hub, udev->portnum); usb_autopm_put_interface(intf); return 0; } enum hub_activation_type { HUB_INIT, HUB_INIT2, HUB_INIT3, /* INITs must come first */ HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME, }; static void hub_init_func2(struct work_struct *ws); static void hub_init_func3(struct work_struct *ws); static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) { struct usb_device *hdev = hub->hdev; struct usb_hcd *hcd; int ret; int port1; int status; bool need_debounce_delay = false; unsigned delay; /* Continue a partial initialization */ if (type == HUB_INIT2) goto init2; if (type == HUB_INIT3) goto init3; /* The superspeed hub except for root hub has to use Hub Depth * value as an offset into the route string to locate the bits * it uses to determine the downstream port number. So hub driver * should send a set hub depth request to superspeed hub after * the superspeed hub is set configuration in initialization or * reset procedure. * * After a resume, port power should still be on. * For any other type of activation, turn it on. */ if (type != HUB_RESUME) { if (hdev->parent && hub_is_superspeed(hdev)) { ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), HUB_SET_DEPTH, USB_RT_HUB, hdev->level - 1, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (ret < 0) dev_err(hub->intfdev, "set hub depth failed\n"); } /* Speed up system boot by using a delayed_work for the * hub's initial power-up delays. This is pretty awkward * and the implementation looks like a home-brewed sort of * setjmp/longjmp, but it saves at least 100 ms for each * root hub (assuming usbcore is compiled into the kernel * rather than as a module). It adds up. * * This can't be done for HUB_RESUME or HUB_RESET_RESUME * because for those activation types the ports have to be * operational when we return. In theory this could be done * for HUB_POST_RESET, but it's easier not to. */ if (type == HUB_INIT) { delay = hub_power_on(hub, false); PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2); schedule_delayed_work(&hub->init_work, msecs_to_jiffies(delay)); /* Suppress autosuspend until init is done */ usb_autopm_get_interface_no_resume( to_usb_interface(hub->intfdev)); return; /* Continues at init2: below */ } else if (type == HUB_RESET_RESUME) { /* The internal host controller state for the hub device * may be gone after a host power loss on system resume. * Update the device's info so the HW knows it's a hub. */ hcd = bus_to_hcd(hdev->bus); if (hcd->driver->update_hub_device) { ret = hcd->driver->update_hub_device(hcd, hdev, &hub->tt, GFP_NOIO); if (ret < 0) { dev_err(hub->intfdev, "Host not " "accepting hub info " "update.\n"); dev_err(hub->intfdev, "LS/FS devices " "and hubs may not work " "under this hub\n."); } } hub_power_on(hub, true); } else { hub_power_on(hub, true); } } init2: /* Check each port and set hub->change_bits to let khubd know * which ports need attention. */ for (port1 = 1; port1 <= hdev->maxchild; ++port1) { struct usb_device *udev = hdev->children[port1-1]; u16 portstatus, portchange; portstatus = portchange = 0; status = hub_port_status(hub, port1, &portstatus, &portchange); if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) dev_dbg(hub->intfdev, "port %d: status %04x change %04x\n", port1, portstatus, portchange); /* After anything other than HUB_RESUME (i.e., initialization * or any sort of reset), every port should be disabled. * Unconnected ports should likewise be disabled (paranoia), * and so should ports for which we have no usb_device. */ if ((portstatus & USB_PORT_STAT_ENABLE) && ( type != HUB_RESUME || !(portstatus & USB_PORT_STAT_CONNECTION) || !udev || udev->state == USB_STATE_NOTATTACHED)) { /* * USB3 protocol ports will automatically transition * to Enabled state when detect an USB3.0 device attach. * Do not disable USB3 protocol ports. */ if (!hub_is_superspeed(hdev)) { clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE); portstatus &= ~USB_PORT_STAT_ENABLE; } else { /* Pretend that power was lost for USB3 devs */ portstatus &= ~USB_PORT_STAT_ENABLE; } } /* Clear status-change flags; we'll debounce later */ if (portchange & USB_PORT_STAT_C_CONNECTION) { need_debounce_delay = true; clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_CONNECTION); } if (portchange & USB_PORT_STAT_C_ENABLE) { need_debounce_delay = true; clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_ENABLE); } if (portchange & USB_PORT_STAT_C_LINK_STATE) { need_debounce_delay = true; clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_PORT_LINK_STATE); } if ((portchange & USB_PORT_STAT_C_BH_RESET) && hub_is_superspeed(hub->hdev)) { need_debounce_delay = true; clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_BH_PORT_RESET); } /* We can forget about a "removed" device when there's a * physical disconnect or the connect status changes. */ if (!(portstatus & USB_PORT_STAT_CONNECTION) || (portchange & USB_PORT_STAT_C_CONNECTION)) clear_bit(port1, hub->removed_bits); if (!udev || udev->state == USB_STATE_NOTATTACHED) { /* Tell khubd to disconnect the device or * check for a new connection */ if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) set_bit(port1, hub->change_bits); } else if (portstatus & USB_PORT_STAT_ENABLE) { /* The power session apparently survived the resume. * If there was an overcurrent or suspend change * (i.e., remote wakeup request), have khubd * take care of it. */ if (portchange) set_bit(port1, hub->change_bits); } else if (udev->persist_enabled) { #ifdef CONFIG_PM udev->reset_resume = 1; #endif set_bit(port1, hub->change_bits); } else { /* The power session is gone; tell khubd */ usb_set_device_state(udev, USB_STATE_NOTATTACHED); set_bit(port1, hub->change_bits); } } /* If no port-status-change flags were set, we don't need any * debouncing. If flags were set we can try to debounce the * ports all at once right now, instead of letting khubd do them * one at a time later on. * * If any port-status changes do occur during this delay, khubd * will see them later and handle them normally. */ if (need_debounce_delay) { delay = HUB_DEBOUNCE_STABLE; /* Don't do a long sleep inside a workqueue routine */ if (type == HUB_INIT2) { PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3); schedule_delayed_work(&hub->init_work, msecs_to_jiffies(delay)); return; /* Continues at init3: below */ } else { msleep(delay); } } init3: hub->quiescing = 0; status = usb_submit_urb(hub->urb, GFP_NOIO); if (status < 0) dev_err(hub->intfdev, "activate --> %d\n", status); if (hub->has_indicators && blinkenlights) schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD); /* Scan all ports that need attention */ kick_khubd(hub); /* Allow autosuspend if it was suppressed */ if (type <= HUB_INIT3) usb_autopm_put_interface_async(to_usb_interface(hub->intfdev)); } /* Implement the continuations for the delays above */ static void hub_init_func2(struct work_struct *ws) { struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work); hub_activate(hub, HUB_INIT2); } static void hub_init_func3(struct work_struct *ws) { struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work); hub_activate(hub, HUB_INIT3); } enum hub_quiescing_type { HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND }; static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type) { struct usb_device *hdev = hub->hdev; int i; cancel_delayed_work_sync(&hub->init_work); /* khubd and related activity won't re-trigger */ hub->quiescing = 1; if (type != HUB_SUSPEND) { /* Disconnect all the children */ for (i = 0; i < hdev->maxchild; ++i) { if (hdev->children[i]) usb_disconnect(&hdev->children[i]); } } /* Stop khubd and related activity */ usb_kill_urb(hub->urb); if (hub->has_indicators) cancel_delayed_work_sync(&hub->leds); if (hub->tt.hub) cancel_work_sync(&hub->tt.clear_work); } /* caller has locked the hub device */ static int hub_pre_reset(struct usb_interface *intf) { struct usb_hub *hub = usb_get_intfdata(intf); hub_quiesce(hub, HUB_PRE_RESET); return 0; } /* caller has locked the hub device */ static int hub_post_reset(struct usb_interface *intf) { struct usb_hub *hub = usb_get_intfdata(intf); hub_activate(hub, HUB_POST_RESET); return 0; } static int hub_configure(struct usb_hub *hub, struct usb_endpoint_descriptor *endpoint) { struct usb_hcd *hcd; struct usb_device *hdev = hub->hdev; struct device *hub_dev = hub->intfdev; u16 hubstatus, hubchange; u16 wHubCharacteristics; unsigned int pipe; int maxp, ret; char *message = "out of memory"; hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL); if (!hub->buffer) { ret = -ENOMEM; goto fail; } hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL); if (!hub->status) { ret = -ENOMEM; goto fail; } mutex_init(&hub->status_mutex); hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL); if (!hub->descriptor) { ret = -ENOMEM; goto fail; } /* Request the entire hub descriptor. * hub->descriptor can handle USB_MAXCHILDREN ports, * but the hub can/will return fewer bytes here. */ ret = get_hub_descriptor(hdev, hub->descriptor); if (ret < 0) { message = "can't read hub descriptor"; goto fail; } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) { message = "hub has too many ports!"; ret = -ENODEV; goto fail; } hdev->maxchild = hub->descriptor->bNbrPorts; dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild, (hdev->maxchild == 1) ? "" : "s"); hub->port_owners = kzalloc(hdev->maxchild * sizeof(void *), GFP_KERNEL); if (!hub->port_owners) { ret = -ENOMEM; goto fail; } wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics); /* FIXME for USB 3.0, skip for now */ if ((wHubCharacteristics & HUB_CHAR_COMPOUND) && !(hub_is_superspeed(hdev))) { int i; char portstr [USB_MAXCHILDREN + 1]; for (i = 0; i < hdev->maxchild; i++) portstr[i] = hub->descriptor->u.hs.DeviceRemovable [((i + 1) / 8)] & (1 << ((i + 1) % 8)) ? 'F' : 'R'; portstr[hdev->maxchild] = 0; dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr); } else dev_dbg(hub_dev, "standalone hub\n"); switch (wHubCharacteristics & HUB_CHAR_LPSM) { case HUB_CHAR_COMMON_LPSM: dev_dbg(hub_dev, "ganged power switching\n"); break; case HUB_CHAR_INDV_PORT_LPSM: dev_dbg(hub_dev, "individual port power switching\n"); break; case HUB_CHAR_NO_LPSM: case HUB_CHAR_LPSM: dev_dbg(hub_dev, "no power switching (usb 1.0)\n"); break; } switch (wHubCharacteristics & HUB_CHAR_OCPM) { case HUB_CHAR_COMMON_OCPM: dev_dbg(hub_dev, "global over-current protection\n"); break; case HUB_CHAR_INDV_PORT_OCPM: dev_dbg(hub_dev, "individual port over-current protection\n"); break; case HUB_CHAR_NO_OCPM: case HUB_CHAR_OCPM: dev_dbg(hub_dev, "no over-current protection\n"); break; } spin_lock_init (&hub->tt.lock); INIT_LIST_HEAD (&hub->tt.clear_list); INIT_WORK(&hub->tt.clear_work, hub_tt_work); switch (hdev->descriptor.bDeviceProtocol) { case USB_HUB_PR_FS: break; case USB_HUB_PR_HS_SINGLE_TT: dev_dbg(hub_dev, "Single TT\n"); hub->tt.hub = hdev; break; case USB_HUB_PR_HS_MULTI_TT: ret = usb_set_interface(hdev, 0, 1); if (ret == 0) { dev_dbg(hub_dev, "TT per port\n"); hub->tt.multi = 1; } else dev_err(hub_dev, "Using single TT (err %d)\n", ret); hub->tt.hub = hdev; break; case USB_HUB_PR_SS: /* USB 3.0 hubs don't have a TT */ break; default: dev_dbg(hub_dev, "Unrecognized hub protocol %d\n", hdev->descriptor.bDeviceProtocol); break; } /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */ switch (wHubCharacteristics & HUB_CHAR_TTTT) { case HUB_TTTT_8_BITS: if (hdev->descriptor.bDeviceProtocol != 0) { hub->tt.think_time = 666; dev_dbg(hub_dev, "TT requires at most %d " "FS bit times (%d ns)\n", 8, hub->tt.think_time); } break; case HUB_TTTT_16_BITS: hub->tt.think_time = 666 * 2; dev_dbg(hub_dev, "TT requires at most %d " "FS bit times (%d ns)\n", 16, hub->tt.think_time); break; case HUB_TTTT_24_BITS: hub->tt.think_time = 666 * 3; dev_dbg(hub_dev, "TT requires at most %d " "FS bit times (%d ns)\n", 24, hub->tt.think_time); break; case HUB_TTTT_32_BITS: hub->tt.think_time = 666 * 4; dev_dbg(hub_dev, "TT requires at most %d " "FS bit times (%d ns)\n", 32, hub->tt.think_time); break; } /* probe() zeroes hub->indicator[] */ if (wHubCharacteristics & HUB_CHAR_PORTIND) { hub->has_indicators = 1; dev_dbg(hub_dev, "Port indicators are supported\n"); } dev_dbg(hub_dev, "power on to power good time: %dms\n", hub->descriptor->bPwrOn2PwrGood * 2); /* power budgeting mostly matters with bus-powered hubs, * and battery-powered root hubs (may provide just 8 mA). */ ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus); if (ret < 2) { message = "can't get hub status"; goto fail; } le16_to_cpus(&hubstatus); if (hdev == hdev->bus->root_hub) { if (hdev->bus_mA == 0 || hdev->bus_mA >= 500) hub->mA_per_port = 500; else { hub->mA_per_port = hdev->bus_mA; hub->limited_power = 1; } } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) { dev_dbg(hub_dev, "hub controller current requirement: %dmA\n", hub->descriptor->bHubContrCurrent); hub->limited_power = 1; if (hdev->maxchild > 0) { int remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent; if (remaining < hdev->maxchild * 100) dev_warn(hub_dev, "insufficient power available " "to use all downstream ports\n"); hub->mA_per_port = 100; /* 7.2.1.1 */ } } else { /* Self-powered external hub */ /* FIXME: What about battery-powered external hubs that * provide less current per port? */ hub->mA_per_port = 500; } if (hub->mA_per_port < 500) dev_dbg(hub_dev, "%umA bus power budget for each child\n", hub->mA_per_port); /* Update the HCD's internal representation of this hub before khubd * starts getting port status changes for devices under the hub. */ hcd = bus_to_hcd(hdev->bus); if (hcd->driver->update_hub_device) { ret = hcd->driver->update_hub_device(hcd, hdev, &hub->tt, GFP_KERNEL); if (ret < 0) { message = "can't update HCD hub info"; goto fail; } } ret = hub_hub_status(hub, &hubstatus, &hubchange); if (ret < 0) { message = "can't get hub status"; goto fail; } /* local power status reports aren't always correct */ if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER) dev_dbg(hub_dev, "local power source is %s\n", (hubstatus & HUB_STATUS_LOCAL_POWER) ? "lost (inactive)" : "good"); if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0) dev_dbg(hub_dev, "%sover-current condition exists\n", (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no "); /* set up the interrupt endpoint * We use the EP's maxpacket size instead of (PORTS+1+7)/8 * bytes as USB2.0[11.12.3] says because some hubs are known * to send more data (and thus cause overflow). For root hubs, * maxpktsize is defined in hcd.c's fake endpoint descriptors * to be big enough for at least USB_MAXCHILDREN ports. */ pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress); maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe)); if (maxp > sizeof(*hub->buffer)) maxp = sizeof(*hub->buffer); hub->urb = usb_alloc_urb(0, GFP_KERNEL); if (!hub->urb) { ret = -ENOMEM; goto fail; } usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq, hub, endpoint->bInterval); /* maybe cycle the hub leds */ if (hub->has_indicators && blinkenlights) hub->indicator [0] = INDICATOR_CYCLE; hub_activate(hub, HUB_INIT); return 0; fail: dev_err (hub_dev, "config failed, %s (err %d)\n", message, ret); /* hub_disconnect() frees urb and descriptor */ return ret; } static void hub_release(struct kref *kref) { struct usb_hub *hub = container_of(kref, struct usb_hub, kref); usb_put_intf(to_usb_interface(hub->intfdev)); kfree(hub); } static unsigned highspeed_hubs; static void hub_disconnect(struct usb_interface *intf) { struct usb_hub *hub = usb_get_intfdata (intf); /* Take the hub off the event list and don't let it be added again */ spin_lock_irq(&hub_event_lock); if (!list_empty(&hub->event_list)) { list_del_init(&hub->event_list); usb_autopm_put_interface_no_suspend(intf); } hub->disconnected = 1; spin_unlock_irq(&hub_event_lock); /* Disconnect all children and quiesce the hub */ hub->error = 0; hub_quiesce(hub, HUB_DISCONNECT); usb_set_intfdata (intf, NULL); hub->hdev->maxchild = 0; if (hub->hdev->speed == USB_SPEED_HIGH) highspeed_hubs--; usb_free_urb(hub->urb); kfree(hub->port_owners); kfree(hub->descriptor); kfree(hub->status); kfree(hub->buffer); kref_put(&hub->kref, hub_release); } static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id) { struct usb_host_interface *desc; struct usb_endpoint_descriptor *endpoint; struct usb_device *hdev; struct usb_hub *hub; desc = intf->cur_altsetting; hdev = interface_to_usbdev(intf); /* Hubs have proper suspend/resume support. USB 3.0 device suspend is * different from USB 2.0/1.1 device suspend, and unfortunately we * don't support it yet. So leave autosuspend disabled for USB 3.0 * external hubs for now. Enable autosuspend for USB 3.0 roothubs, * since that isn't a "real" hub. */ if (!hub_is_superspeed(hdev) || !hdev->parent) usb_enable_autosuspend(hdev); if (hdev->level == MAX_TOPO_LEVEL) { dev_err(&intf->dev, "Unsupported bus topology: hub nested too deep\n"); return -E2BIG; } #ifdef CONFIG_USB_OTG_BLACKLIST_HUB if (hdev->parent) { dev_warn(&intf->dev, "ignoring external hub\n"); return -ENODEV; } #endif /* Some hubs have a subclass of 1, which AFAICT according to the */ /* specs is not defined, but it works */ if ((desc->desc.bInterfaceSubClass != 0) && (desc->desc.bInterfaceSubClass != 1)) { descriptor_error: dev_err (&intf->dev, "bad descriptor, ignoring hub\n"); return -EIO; } /* Multiple endpoints? What kind of mutant ninja-hub is this? */ if (desc->desc.bNumEndpoints != 1) goto descriptor_error; endpoint = &desc->endpoint[0].desc; /* If it's not an interrupt in endpoint, we'd better punt! */ if (!usb_endpoint_is_int_in(endpoint)) goto descriptor_error; /* We found a hub */ dev_info (&intf->dev, "USB hub found\n"); hub = kzalloc(sizeof(*hub), GFP_KERNEL); if (!hub) { dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n"); return -ENOMEM; } kref_init(&hub->kref); INIT_LIST_HEAD(&hub->event_list); hub->intfdev = &intf->dev; hub->hdev = hdev; INIT_DELAYED_WORK(&hub->leds, led_work); INIT_DELAYED_WORK(&hub->init_work, NULL); usb_get_intf(intf); usb_set_intfdata (intf, hub); intf->needs_remote_wakeup = 1; if (hdev->speed == USB_SPEED_HIGH) highspeed_hubs++; if (hub_configure(hub, endpoint) >= 0) return 0; hub_disconnect (intf); return -ENODEV; } static int hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data) { struct usb_device *hdev = interface_to_usbdev (intf); /* assert ifno == 0 (part of hub spec) */ switch (code) { case USBDEVFS_HUB_PORTINFO: { struct usbdevfs_hub_portinfo *info = user_data; int i; spin_lock_irq(&device_state_lock); if (hdev->devnum <= 0) info->nports = 0; else { info->nports = hdev->maxchild; for (i = 0; i < info->nports; i++) { if (hdev->children[i] == NULL) info->port[i] = 0; else info->port[i] = hdev->children[i]->devnum; } } spin_unlock_irq(&device_state_lock); return info->nports + 1; } default: return -ENOSYS; } } /* * Allow user programs to claim ports on a hub. When a device is attached * to one of these "claimed" ports, the program will "own" the device. */ static int find_port_owner(struct usb_device *hdev, unsigned port1, void ***ppowner) { if (hdev->state == USB_STATE_NOTATTACHED) return -ENODEV; if (port1 == 0 || port1 > hdev->maxchild) return -EINVAL; /* This assumes that devices not managed by the hub driver * will always have maxchild equal to 0. */ *ppowner = &(hdev_to_hub(hdev)->port_owners[port1 - 1]); return 0; } /* In the following three functions, the caller must hold hdev's lock */ int usb_hub_claim_port(struct usb_device *hdev, unsigned port1, void *owner) { int rc; void **powner; rc = find_port_owner(hdev, port1, &powner); if (rc) return rc; if (*powner) return -EBUSY; *powner = owner; return rc; } int usb_hub_release_port(struct usb_device *hdev, unsigned port1, void *owner) { int rc; void **powner; rc = find_port_owner(hdev, port1, &powner); if (rc) return rc; if (*powner != owner) return -ENOENT; *powner = NULL; return rc; } void usb_hub_release_all_ports(struct usb_device *hdev, void *owner) { int n; void **powner; n = find_port_owner(hdev, 1, &powner); if (n == 0) { for (; n < hdev->maxchild; (++n, ++powner)) { if (*powner == owner) *powner = NULL; } } } /* The caller must hold udev's lock */ bool usb_device_is_owned(struct usb_device *udev) { struct usb_hub *hub; if (udev->state == USB_STATE_NOTATTACHED || !udev->parent) return false; hub = hdev_to_hub(udev->parent); return !!hub->port_owners[udev->portnum - 1]; } static void recursively_mark_NOTATTACHED(struct usb_device *udev) { int i; for (i = 0; i < udev->maxchild; ++i) { if (udev->children[i]) recursively_mark_NOTATTACHED(udev->children[i]); } if (udev->state == USB_STATE_SUSPENDED) udev->active_duration -= jiffies; udev->state = USB_STATE_NOTATTACHED; } /** * usb_set_device_state - change a device's current state (usbcore, hcds) * @udev: pointer to device whose state should be changed * @new_state: new state value to be stored * * udev->state is _not_ fully protected by the device lock. Although * most transitions are made only while holding the lock, the state can * can change to USB_STATE_NOTATTACHED at almost any time. This * is so that devices can be marked as disconnected as soon as possible, * without having to wait for any semaphores to be released. As a result, * all changes to any device's state must be protected by the * device_state_lock spinlock. * * Once a device has been added to the device tree, all changes to its state * should be made using this routine. The state should _not_ be set directly. * * If udev->state is already USB_STATE_NOTATTACHED then no change is made. * Otherwise udev->state is set to new_state, and if new_state is * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set * to USB_STATE_NOTATTACHED. */ void usb_set_device_state(struct usb_device *udev, enum usb_device_state new_state) { unsigned long flags; int wakeup = -1; spin_lock_irqsave(&device_state_lock, flags); if (udev->state == USB_STATE_NOTATTACHED) ; /* do nothing */ else if (new_state != USB_STATE_NOTATTACHED) { /* root hub wakeup capabilities are managed out-of-band * and may involve silicon errata ... ignore them here. */ if (udev->parent) { if (udev->state == USB_STATE_SUSPENDED || new_state == USB_STATE_SUSPENDED) ; /* No change to wakeup settings */ else if (new_state == USB_STATE_CONFIGURED) wakeup = udev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_WAKEUP; else wakeup = 0; } if (udev->state == USB_STATE_SUSPENDED && new_state != USB_STATE_SUSPENDED) udev->active_duration -= jiffies; else if (new_state == USB_STATE_SUSPENDED && udev->state != USB_STATE_SUSPENDED) udev->active_duration += jiffies; udev->state = new_state; } else recursively_mark_NOTATTACHED(udev); spin_unlock_irqrestore(&device_state_lock, flags); if (wakeup >= 0) device_set_wakeup_capable(&udev->dev, wakeup); } EXPORT_SYMBOL_GPL(usb_set_device_state); /* * Choose a device number. * * Device numbers are used as filenames in usbfs. On USB-1.1 and * USB-2.0 buses they are also used as device addresses, however on * USB-3.0 buses the address is assigned by the controller hardware * and it usually is not the same as the device number. * * WUSB devices are simple: they have no hubs behind, so the mapping * device <-> virtual port number becomes 1:1. Why? to simplify the * life of the device connection logic in * drivers/usb/wusbcore/devconnect.c. When we do the initial secret * handshake we need to assign a temporary address in the unauthorized * space. For simplicity we use the first virtual port number found to * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()] * and that becomes it's address [X < 128] or its unauthorized address * [X | 0x80]. * * We add 1 as an offset to the one-based USB-stack port number * (zero-based wusb virtual port index) for two reasons: (a) dev addr * 0 is reserved by USB for default address; (b) Linux's USB stack * uses always #1 for the root hub of the controller. So USB stack's * port #1, which is wusb virtual-port #0 has address #2. * * Devices connected under xHCI are not as simple. The host controller * supports virtualization, so the hardware assigns device addresses and * the HCD must setup data structures before issuing a set address * command to the hardware. */ static void choose_devnum(struct usb_device *udev) { int devnum; struct usb_bus *bus = udev->bus; /* If khubd ever becomes multithreaded, this will need a lock */ if (udev->wusb) { devnum = udev->portnum + 1; BUG_ON(test_bit(devnum, bus->devmap.devicemap)); } else { /* Try to allocate the next devnum beginning at * bus->devnum_next. */ devnum = find_next_zero_bit(bus->devmap.devicemap, 128, bus->devnum_next); if (devnum >= 128) devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1); bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1); } if (devnum < 128) { set_bit(devnum, bus->devmap.devicemap); udev->devnum = devnum; } } static void release_devnum(struct usb_device *udev) { if (udev->devnum > 0) { clear_bit(udev->devnum, udev->bus->devmap.devicemap); udev->devnum = -1; } } static void update_devnum(struct usb_device *udev, int devnum) { /* The address for a WUSB device is managed by wusbcore. */ if (!udev->wusb) udev->devnum = devnum; } static void hub_free_dev(struct usb_device *udev) { struct usb_hcd *hcd = bus_to_hcd(udev->bus); /* Root hubs aren't real devices, so don't free HCD resources */ if (hcd->driver->free_dev && udev->parent) hcd->driver->free_dev(hcd, udev); } /** * usb_disconnect - disconnect a device (usbcore-internal) * @pdev: pointer to device being disconnected * Context: !in_interrupt () * * Something got disconnected. Get rid of it and all of its children. * * If *pdev is a normal device then the parent hub must already be locked. * If *pdev is a root hub then this routine will acquire the * usb_bus_list_lock on behalf of the caller. * * Only hub drivers (including virtual root hub drivers for host * controllers) should ever call this. * * This call is synchronous, and may not be used in an interrupt context. */ void usb_disconnect(struct usb_device **pdev) { struct usb_device *udev = *pdev; int i; struct usb_hcd *hcd = bus_to_hcd(udev->bus); /* mark the device as inactive, so any further urb submissions for * this device (and any of its children) will fail immediately. * this quiesces everything except pending urbs. */ usb_set_device_state(udev, USB_STATE_NOTATTACHED); dev_info(&udev->dev, "USB disconnect, device number %d\n", udev->devnum); usb_lock_device(udev); /* Free up all the children before we remove this device */ for (i = 0; i < USB_MAXCHILDREN; i++) { if (udev->children[i]) usb_disconnect(&udev->children[i]); } /* deallocate hcd/hardware state ... nuking all pending urbs and * cleaning up all state associated with the current configuration * so that the hardware is now fully quiesced. */ dev_dbg (&udev->dev, "unregistering device\n"); mutex_lock(hcd->bandwidth_mutex); usb_disable_device(udev, 0); mutex_unlock(hcd->bandwidth_mutex); usb_hcd_synchronize_unlinks(udev); usb_remove_ep_devs(&udev->ep0); usb_unlock_device(udev); /* Unregister the device. The device driver is responsible * for de-configuring the device and invoking the remove-device * notifier chain (used by usbfs and possibly others). */ device_del(&udev->dev); /* Free the device number and delete the parent's children[] * (or root_hub) pointer. */ release_devnum(udev); /* Avoid races with recursively_mark_NOTATTACHED() */ spin_lock_irq(&device_state_lock); *pdev = NULL; spin_unlock_irq(&device_state_lock); hub_free_dev(udev); put_device(&udev->dev); } #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES static void show_string(struct usb_device *udev, char *id, char *string) { if (!string) return; dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string); } static void announce_device(struct usb_device *udev) { dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n", le16_to_cpu(udev->descriptor.idVendor), le16_to_cpu(udev->descriptor.idProduct)); dev_info(&udev->dev, "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n", udev->descriptor.iManufacturer, udev->descriptor.iProduct, udev->descriptor.iSerialNumber); show_string(udev, "Product", udev->product); show_string(udev, "Manufacturer", udev->manufacturer); show_string(udev, "SerialNumber", udev->serial); } #else static inline void announce_device(struct usb_device *udev) { } #endif #ifdef CONFIG_USB_OTG #include "otg_whitelist.h" #endif /** * usb_enumerate_device_otg - FIXME (usbcore-internal) * @udev: newly addressed device (in ADDRESS state) * * Finish enumeration for On-The-Go devices */ static int usb_enumerate_device_otg(struct usb_device *udev) { int err = 0; #ifdef CONFIG_USB_OTG /* * OTG-aware devices on OTG-capable root hubs may be able to use SRP, * to wake us after we've powered off VBUS; and HNP, switching roles * "host" to "peripheral". The OTG descriptor helps figure this out. */ if (!udev->bus->is_b_host && udev->config && udev->parent == udev->bus->root_hub) { struct usb_otg_descriptor *desc = NULL; struct usb_bus *bus = udev->bus; /* descriptor may appear anywhere in config */ if (__usb_get_extra_descriptor (udev->rawdescriptors[0], le16_to_cpu(udev->config[0].desc.wTotalLength), USB_DT_OTG, (void **) &desc) == 0) { if (desc->bmAttributes & USB_OTG_HNP) { unsigned port1 = udev->portnum; dev_info(&udev->dev, "Dual-Role OTG device on %sHNP port\n", (port1 == bus->otg_port) ? "" : "non-"); /* enable HNP before suspend, it's simpler */ if (port1 == bus->otg_port) bus->b_hnp_enable = 1; err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), USB_REQ_SET_FEATURE, 0, bus->b_hnp_enable ? USB_DEVICE_B_HNP_ENABLE : USB_DEVICE_A_ALT_HNP_SUPPORT, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (err < 0) { /* OTG MESSAGE: report errors here, * customize to match your product. */ dev_info(&udev->dev, "can't set HNP mode: %d\n", err); bus->b_hnp_enable = 0; } } } } if (!is_targeted(udev)) { /* Maybe it can talk to us, though we can't talk to it. * (Includes HNP test device.) */ if (udev->bus->b_hnp_enable || udev->bus->is_b_host) { err = usb_port_suspend(udev, PMSG_SUSPEND); if (err < 0) dev_dbg(&udev->dev, "HNP fail, %d\n", err); } err = -ENOTSUPP; goto fail; } fail: #endif return err; } /** * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal) * @udev: newly addressed device (in ADDRESS state) * * This is only called by usb_new_device() and usb_authorize_device() * and FIXME -- all comments that apply to them apply here wrt to * environment. * * If the device is WUSB and not authorized, we don't attempt to read * the string descriptors, as they will be errored out by the device * until it has been authorized. */ static int usb_enumerate_device(struct usb_device *udev) { int err; if (udev->config == NULL) { err = usb_get_configuration(udev); if (err < 0) { dev_err(&udev->dev, "can't read configurations, error %d\n", err); goto fail; } } if (udev->wusb == 1 && udev->authorized == 0) { udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL); udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL); udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL); } else { /* read the standard strings and cache them if present */ udev->product = usb_cache_string(udev, udev->descriptor.iProduct); udev->manufacturer = usb_cache_string(udev, udev->descriptor.iManufacturer); udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber); } err = usb_enumerate_device_otg(udev); fail: return err; } /** * usb_new_device - perform initial device setup (usbcore-internal) * @udev: newly addressed device (in ADDRESS state) * * This is called with devices which have been detected but not fully * enumerated. The device descriptor is available, but not descriptors * for any device configuration. The caller must have locked either * the parent hub (if udev is a normal device) or else the * usb_bus_list_lock (if udev is a root hub). The parent's pointer to * udev has already been installed, but udev is not yet visible through * sysfs or other filesystem code. * * It will return if the device is configured properly or not. Zero if * the interface was registered with the driver core; else a negative * errno value. * * This call is synchronous, and may not be used in an interrupt context. * * Only the hub driver or root-hub registrar should ever call this. */ int usb_new_device(struct usb_device *udev) { int err; if (udev->parent) { /* Initialize non-root-hub device wakeup to disabled; * device (un)configuration controls wakeup capable * sysfs power/wakeup controls wakeup enabled/disabled */ device_init_wakeup(&udev->dev, 0); } /* Tell the runtime-PM framework the device is active */ pm_runtime_set_active(&udev->dev); pm_runtime_get_noresume(&udev->dev); pm_runtime_use_autosuspend(&udev->dev); pm_runtime_enable(&udev->dev); /* By default, forbid autosuspend for all devices. It will be * allowed for hubs during binding. */ usb_disable_autosuspend(udev); err = usb_enumerate_device(udev); /* Read descriptors */ if (err < 0) goto fail; dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n", udev->devnum, udev->bus->busnum, (((udev->bus->busnum-1) * 128) + (udev->devnum-1))); /* export the usbdev device-node for libusb */ udev->dev.devt = MKDEV(USB_DEVICE_MAJOR, (((udev->bus->busnum-1) * 128) + (udev->devnum-1))); /* Tell the world! */ announce_device(udev); device_enable_async_suspend(&udev->dev); /* Register the device. The device driver is responsible * for configuring the device and invoking the add-device * notifier chain (used by usbfs and possibly others). */ err = device_add(&udev->dev); if (err) { dev_err(&udev->dev, "can't device_add, error %d\n", err); goto fail; } (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev); usb_mark_last_busy(udev); pm_runtime_put_sync_autosuspend(&udev->dev); return err; fail: usb_set_device_state(udev, USB_STATE_NOTATTACHED); pm_runtime_disable(&udev->dev); pm_runtime_set_suspended(&udev->dev); return err; } /** * usb_deauthorize_device - deauthorize a device (usbcore-internal) * @usb_dev: USB device * * Move the USB device to a very basic state where interfaces are disabled * and the device is in fact unconfigured and unusable. * * We share a lock (that we have) with device_del(), so we need to * defer its call. */ int usb_deauthorize_device(struct usb_device *usb_dev) { usb_lock_device(usb_dev); if (usb_dev->authorized == 0) goto out_unauthorized; usb_dev->authorized = 0; usb_set_configuration(usb_dev, -1); kfree(usb_dev->product); usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL); kfree(usb_dev->manufacturer); usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL); kfree(usb_dev->serial); usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL); usb_destroy_configuration(usb_dev); usb_dev->descriptor.bNumConfigurations = 0; out_unauthorized: usb_unlock_device(usb_dev); return 0; } int usb_authorize_device(struct usb_device *usb_dev) { int result = 0, c; usb_lock_device(usb_dev); if (usb_dev->authorized == 1) goto out_authorized; result = usb_autoresume_device(usb_dev); if (result < 0) { dev_err(&usb_dev->dev, "can't autoresume for authorization: %d\n", result); goto error_autoresume; } result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor)); if (result < 0) { dev_err(&usb_dev->dev, "can't re-read device descriptor for " "authorization: %d\n", result); goto error_device_descriptor; } kfree(usb_dev->product); usb_dev->product = NULL; kfree(usb_dev->manufacturer); usb_dev->manufacturer = NULL; kfree(usb_dev->serial); usb_dev->serial = NULL; usb_dev->authorized = 1; result = usb_enumerate_device(usb_dev); if (result < 0) goto error_enumerate; /* Choose and set the configuration. This registers the interfaces * with the driver core and lets interface drivers bind to them. */ c = usb_choose_configuration(usb_dev); if (c >= 0) { result = usb_set_configuration(usb_dev, c); if (result) { dev_err(&usb_dev->dev, "can't set config #%d, error %d\n", c, result); /* This need not be fatal. The user can try to * set other configurations. */ } } dev_info(&usb_dev->dev, "authorized to connect\n"); error_enumerate: error_device_descriptor: usb_autosuspend_device(usb_dev); error_autoresume: out_authorized: usb_unlock_device(usb_dev); // complements locktree return result; } /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */ static unsigned hub_is_wusb(struct usb_hub *hub) { struct usb_hcd *hcd; if (hub->hdev->parent != NULL) /* not a root hub? */ return 0; hcd = container_of(hub->hdev->bus, struct usb_hcd, self); return hcd->wireless; } #define PORT_RESET_TRIES 5 #define SET_ADDRESS_TRIES 2 #define GET_DESCRIPTOR_TRIES 2 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1)) #define USE_NEW_SCHEME(i) ((i) / 2 == (int)old_scheme_first) #define HUB_ROOT_RESET_TIME 50 /* times are in msec */ #define HUB_SHORT_RESET_TIME 10 #define HUB_BH_RESET_TIME 50 #define HUB_LONG_RESET_TIME 200 #define HUB_RESET_TIMEOUT 500 static int hub_port_reset(struct usb_hub *hub, int port1, struct usb_device *udev, unsigned int delay, bool warm); /* Is a USB 3.0 port in the Inactive state? */ static bool hub_port_inactive(struct usb_hub *hub, u16 portstatus) { return hub_is_superspeed(hub->hdev) && (portstatus & USB_PORT_STAT_LINK_STATE) == USB_SS_PORT_LS_SS_INACTIVE; } static int hub_port_wait_reset(struct usb_hub *hub, int port1, struct usb_device *udev, unsigned int delay, bool warm) { int delay_time, ret; u16 portstatus; u16 portchange; for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT; delay_time += delay) { /* wait to give the device a chance to reset */ msleep(delay); /* read and decode port status */ ret = hub_port_status(hub, port1, &portstatus, &portchange); if (ret < 0) return ret; /* * Some buggy devices require a warm reset to be issued even * when the port appears not to be connected. */ if (!warm) { /* * Some buggy devices can cause an NEC host controller * to transition to the "Error" state after a hot port * reset. This will show up as the port state in * "Inactive", and the port may also report a * disconnect. Forcing a warm port reset seems to make * the device work. * * See https://bugzilla.kernel.org/show_bug.cgi?id=41752 */ if (hub_port_inactive(hub, portstatus)) { int ret; if ((portchange & USB_PORT_STAT_C_CONNECTION)) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_CONNECTION); if (portchange & USB_PORT_STAT_C_LINK_STATE) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_PORT_LINK_STATE); if (portchange & USB_PORT_STAT_C_RESET) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_RESET); dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n", port1); ret = hub_port_reset(hub, port1, udev, HUB_BH_RESET_TIME, true); if ((portchange & USB_PORT_STAT_C_CONNECTION)) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_CONNECTION); return ret; } /* Device went away? */ if (!(portstatus & USB_PORT_STAT_CONNECTION)) return -ENOTCONN; /* bomb out completely if the connection bounced */ if ((portchange & USB_PORT_STAT_C_CONNECTION)) return -ENOTCONN; /* if we`ve finished resetting, then break out of * the loop */ if (!(portstatus & USB_PORT_STAT_RESET) && (portstatus & USB_PORT_STAT_ENABLE)) { if (hub_is_wusb(hub)) udev->speed = USB_SPEED_WIRELESS; else if (hub_is_superspeed(hub->hdev)) udev->speed = USB_SPEED_SUPER; else if (portstatus & USB_PORT_STAT_HIGH_SPEED) udev->speed = USB_SPEED_HIGH; else if (portstatus & USB_PORT_STAT_LOW_SPEED) udev->speed = USB_SPEED_LOW; else udev->speed = USB_SPEED_FULL; return 0; } } else { if (portchange & USB_PORT_STAT_C_BH_RESET) return 0; } /* switch to the long delay after two short delay failures */ if (delay_time >= 2 * HUB_SHORT_RESET_TIME) delay = HUB_LONG_RESET_TIME; dev_dbg (hub->intfdev, "port %d not %sreset yet, waiting %dms\n", port1, warm ? "warm " : "", delay); } return -EBUSY; } static void hub_port_finish_reset(struct usb_hub *hub, int port1, struct usb_device *udev, int *status, bool warm) { switch (*status) { case 0: if (!warm) { struct usb_hcd *hcd; /* TRSTRCY = 10 ms; plus some extra */ msleep(10 + 40); update_devnum(udev, 0); hcd = bus_to_hcd(udev->bus); if (hcd->driver->reset_device) { *status = hcd->driver->reset_device(hcd, udev); if (*status < 0) { dev_err(&udev->dev, "Cannot reset " "HCD device state\n"); break; } } } /* FALL THROUGH */ case -ENOTCONN: case -ENODEV: clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_RESET); /* FIXME need disconnect() for NOTATTACHED device */ if (warm) { clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_BH_PORT_RESET); clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_PORT_LINK_STATE); } else { usb_set_device_state(udev, *status ? USB_STATE_NOTATTACHED : USB_STATE_DEFAULT); } break; } } /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */ static int hub_port_reset(struct usb_hub *hub, int port1, struct usb_device *udev, unsigned int delay, bool warm) { int i, status; if (!warm) { /* Block EHCI CF initialization during the port reset. * Some companion controllers don't like it when they mix. */ down_read(&ehci_cf_port_reset_rwsem); } else { if (!hub_is_superspeed(hub->hdev)) { dev_err(hub->intfdev, "only USB3 hub support " "warm reset\n"); return -EINVAL; } } /* Reset the port */ for (i = 0; i < PORT_RESET_TRIES; i++) { status = set_port_feature(hub->hdev, port1, (warm ? USB_PORT_FEAT_BH_PORT_RESET : USB_PORT_FEAT_RESET)); if (status) { dev_err(hub->intfdev, "cannot %sreset port %d (err = %d)\n", warm ? "warm " : "", port1, status); } else { status = hub_port_wait_reset(hub, port1, udev, delay, warm); if (status && status != -ENOTCONN) dev_dbg(hub->intfdev, "port_wait_reset: err = %d\n", status); } /* return on disconnect or reset */ if (status == 0 || status == -ENOTCONN || status == -ENODEV) { hub_port_finish_reset(hub, port1, udev, &status, warm); goto done; } dev_dbg (hub->intfdev, "port %d not enabled, trying %sreset again...\n", port1, warm ? "warm " : ""); delay = HUB_LONG_RESET_TIME; } dev_err (hub->intfdev, "Cannot enable port %i. Maybe the USB cable is bad?\n", port1); done: if (!warm) up_read(&ehci_cf_port_reset_rwsem); return status; } /* Check if a port is power on */ static int port_is_power_on(struct usb_hub *hub, unsigned portstatus) { int ret = 0; if (hub_is_superspeed(hub->hdev)) { if (portstatus & USB_SS_PORT_STAT_POWER) ret = 1; } else { if (portstatus & USB_PORT_STAT_POWER) ret = 1; } return ret; } #ifdef CONFIG_PM /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */ static int port_is_suspended(struct usb_hub *hub, unsigned portstatus) { int ret = 0; if (hub_is_superspeed(hub->hdev)) { if ((portstatus & USB_PORT_STAT_LINK_STATE) == USB_SS_PORT_LS_U3) ret = 1; } else { if (portstatus & USB_PORT_STAT_SUSPEND) ret = 1; } return ret; } /* Determine whether the device on a port is ready for a normal resume, * is ready for a reset-resume, or should be disconnected. */ static int check_port_resume_type(struct usb_device *udev, struct usb_hub *hub, int port1, int status, unsigned portchange, unsigned portstatus) { /* Is the device still present? */ if (status || port_is_suspended(hub, portstatus) || !port_is_power_on(hub, portstatus) || !(portstatus & USB_PORT_STAT_CONNECTION)) { if (status >= 0) status = -ENODEV; } /* Can't do a normal resume if the port isn't enabled, * so try a reset-resume instead. */ else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) { if (udev->persist_enabled) udev->reset_resume = 1; else status = -ENODEV; } if (status) { dev_dbg(hub->intfdev, "port %d status %04x.%04x after resume, %d\n", port1, portchange, portstatus, status); } else if (udev->reset_resume) { /* Late port handoff can set status-change bits */ if (portchange & USB_PORT_STAT_C_CONNECTION) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_CONNECTION); if (portchange & USB_PORT_STAT_C_ENABLE) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_ENABLE); } return status; } #ifdef CONFIG_USB_SUSPEND /* * usb_port_suspend - suspend a usb device's upstream port * @udev: device that's no longer in active use, not a root hub * Context: must be able to sleep; device not locked; pm locks held * * Suspends a USB device that isn't in active use, conserving power. * Devices may wake out of a suspend, if anything important happens, * using the remote wakeup mechanism. They may also be taken out of * suspend by the host, using usb_port_resume(). It's also routine * to disconnect devices while they are suspended. * * This only affects the USB hardware for a device; its interfaces * (and, for hubs, child devices) must already have been suspended. * * Selective port suspend reduces power; most suspended devices draw * less than 500 uA. It's also used in OTG, along with remote wakeup. * All devices below the suspended port are also suspended. * * Devices leave suspend state when the host wakes them up. Some devices * also support "remote wakeup", where the device can activate the USB * tree above them to deliver data, such as a keypress or packet. In * some cases, this wakes the USB host. * * Suspending OTG devices may trigger HNP, if that's been enabled * between a pair of dual-role devices. That will change roles, such * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral. * * Devices on USB hub ports have only one "suspend" state, corresponding * to ACPI D2, "may cause the device to lose some context". * State transitions include: * * - suspend, resume ... when the VBUS power link stays live * - suspend, disconnect ... VBUS lost * * Once VBUS drop breaks the circuit, the port it's using has to go through * normal re-enumeration procedures, starting with enabling VBUS power. * Other than re-initializing the hub (plug/unplug, except for root hubs), * Linux (2.6) currently has NO mechanisms to initiate that: no khubd * timer, no SRP, no requests through sysfs. * * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when * the root hub for their bus goes into global suspend ... so we don't * (falsely) update the device power state to say it suspended. * * Returns 0 on success, else negative errno. */ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) { struct usb_hub *hub = hdev_to_hub(udev->parent); int port1 = udev->portnum; int status; /* enable remote wakeup when appropriate; this lets the device * wake up the upstream hub (including maybe the root hub). * * NOTE: OTG devices may issue remote wakeup (or SRP) even when * we don't explicitly enable it here. */ if (udev->do_remote_wakeup) { status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), USB_REQ_SET_FEATURE, USB_RECIP_DEVICE, USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (status) { dev_dbg(&udev->dev, "won't remote wakeup, status %d\n", status); /* bail if autosuspend is requested */ if (PMSG_IS_AUTO(msg)) return status; } } /* disable USB2 hardware LPM */ if (udev->usb2_hw_lpm_enabled == 1) usb_set_usb2_hardware_lpm(udev, 0); /* see 7.1.7.6 */ if (hub_is_superspeed(hub->hdev)) status = set_port_feature(hub->hdev, port1 | (USB_SS_PORT_LS_U3 << 3), USB_PORT_FEAT_LINK_STATE); else status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND); if (status) { dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n", port1, status); /* paranoia: "should not happen" */ if (udev->do_remote_wakeup) (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0), USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE, USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); /* System sleep transitions should never fail */ if (!PMSG_IS_AUTO(msg)) status = 0; } else { /* device has up to 10 msec to fully suspend */ dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n", (PMSG_IS_AUTO(msg) ? "auto-" : ""), udev->do_remote_wakeup); usb_set_device_state(udev, USB_STATE_SUSPENDED); msleep(10); } usb_mark_last_busy(hub->hdev); return status; } /* * If the USB "suspend" state is in use (rather than "global suspend"), * many devices will be individually taken out of suspend state using * special "resume" signaling. This routine kicks in shortly after * hardware resume signaling is finished, either because of selective * resume (by host) or remote wakeup (by device) ... now see what changed * in the tree that's rooted at this device. * * If @udev->reset_resume is set then the device is reset before the * status check is done. */ static int finish_port_resume(struct usb_device *udev) { int status = 0; u16 devstatus; /* caller owns the udev device lock */ dev_dbg(&udev->dev, "%s\n", udev->reset_resume ? "finish reset-resume" : "finish resume"); /* usb ch9 identifies four variants of SUSPENDED, based on what * state the device resumes to. Linux currently won't see the * first two on the host side; they'd be inside hub_port_init() * during many timeouts, but khubd can't suspend until later. */ usb_set_device_state(udev, udev->actconfig ? USB_STATE_CONFIGURED : USB_STATE_ADDRESS); /* 10.5.4.5 says not to reset a suspended port if the attached * device is enabled for remote wakeup. Hence the reset * operation is carried out here, after the port has been * resumed. */ if (udev->reset_resume) retry_reset_resume: status = usb_reset_and_verify_device(udev); /* 10.5.4.5 says be sure devices in the tree are still there. * For now let's assume the device didn't go crazy on resume, * and device drivers will know about any resume quirks. */ if (status == 0) { devstatus = 0; status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus); if (status >= 0) status = (status > 0 ? 0 : -ENODEV); /* If a normal resume failed, try doing a reset-resume */ if (status && !udev->reset_resume && udev->persist_enabled) { dev_dbg(&udev->dev, "retry with reset-resume\n"); udev->reset_resume = 1; goto retry_reset_resume; } } if (status) { dev_dbg(&udev->dev, "gone after usb resume? status %d\n", status); } else if (udev->actconfig) { le16_to_cpus(&devstatus); if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) { status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE, USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (status) dev_dbg(&udev->dev, "disable remote wakeup, status %d\n", status); } status = 0; } return status; } /* * usb_port_resume - re-activate a suspended usb device's upstream port * @udev: device to re-activate, not a root hub * Context: must be able to sleep; device not locked; pm locks held * * This will re-activate the suspended device, increasing power usage * while letting drivers communicate again with its endpoints. * USB resume explicitly guarantees that the power session between * the host and the device is the same as it was when the device * suspended. * * If @udev->reset_resume is set then this routine won't check that the * port is still enabled. Furthermore, finish_port_resume() above will * reset @udev. The end result is that a broken power session can be * recovered and @udev will appear to persist across a loss of VBUS power. * * For example, if a host controller doesn't maintain VBUS suspend current * during a system sleep or is reset when the system wakes up, all the USB * power sessions below it will be broken. This is especially troublesome * for mass-storage devices containing mounted filesystems, since the * device will appear to have disconnected and all the memory mappings * to it will be lost. Using the USB_PERSIST facility, the device can be * made to appear as if it had not disconnected. * * This facility can be dangerous. Although usb_reset_and_verify_device() makes * every effort to insure that the same device is present after the * reset as before, it cannot provide a 100% guarantee. Furthermore it's * quite possible for a device to remain unaltered but its media to be * changed. If the user replaces a flash memory card while the system is * asleep, he will have only himself to blame when the filesystem on the * new card is corrupted and the system crashes. * * Returns 0 on success, else negative errno. */ int usb_port_resume(struct usb_device *udev, pm_message_t msg) { struct usb_hub *hub = hdev_to_hub(udev->parent); int port1 = udev->portnum; int status; u16 portchange, portstatus; /* Skip the initial Clear-Suspend step for a remote wakeup */ status = hub_port_status(hub, port1, &portstatus, &portchange); if (status == 0 && !port_is_suspended(hub, portstatus)) goto SuspendCleared; // dev_dbg(hub->intfdev, "resume port %d\n", port1); set_bit(port1, hub->busy_bits); /* see 7.1.7.7; affects power usage, but not budgeting */ if (hub_is_superspeed(hub->hdev)) status = set_port_feature(hub->hdev, port1 | (USB_SS_PORT_LS_U0 << 3), USB_PORT_FEAT_LINK_STATE); else status = clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND); if (status) { dev_dbg(hub->intfdev, "can't resume port %d, status %d\n", port1, status); } else { /* drive resume for at least 20 msec */ dev_dbg(&udev->dev, "usb %sresume\n", (PMSG_IS_AUTO(msg) ? "auto-" : "")); msleep(25); /* Virtual root hubs can trigger on GET_PORT_STATUS to * stop resume signaling. Then finish the resume * sequence. */ status = hub_port_status(hub, port1, &portstatus, &portchange); /* TRSMRCY = 10 msec */ msleep(10); } SuspendCleared: if (status == 0) { if (hub_is_superspeed(hub->hdev)) { if (portchange & USB_PORT_STAT_C_LINK_STATE) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_PORT_LINK_STATE); } else { if (portchange & USB_PORT_STAT_C_SUSPEND) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_SUSPEND); } } clear_bit(port1, hub->busy_bits); status = check_port_resume_type(udev, hub, port1, status, portchange, portstatus); if (status == 0) status = finish_port_resume(udev); if (status < 0) { dev_dbg(&udev->dev, "can't resume, status %d\n", status); hub_port_logical_disconnect(hub, port1); } else { /* Try to enable USB2 hardware LPM */ if (udev->usb2_hw_lpm_capable == 1) usb_set_usb2_hardware_lpm(udev, 1); } return status; } /* caller has locked udev */ int usb_remote_wakeup(struct usb_device *udev) { int status = 0; if (udev->state == USB_STATE_SUSPENDED) { dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-"); status = usb_autoresume_device(udev); if (status == 0) { /* Let the drivers do their thing, then... */ usb_autosuspend_device(udev); } } return status; } #else /* CONFIG_USB_SUSPEND */ /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) { return 0; } /* However we may need to do a reset-resume */ int usb_port_resume(struct usb_device *udev, pm_message_t msg) { struct usb_hub *hub = hdev_to_hub(udev->parent); int port1 = udev->portnum; int status; u16 portchange, portstatus; status = hub_port_status(hub, port1, &portstatus, &portchange); status = check_port_resume_type(udev, hub, port1, status, portchange, portstatus); if (status) { dev_dbg(&udev->dev, "can't resume, status %d\n", status); hub_port_logical_disconnect(hub, port1); } else if (udev->reset_resume) { dev_dbg(&udev->dev, "reset-resume\n"); status = usb_reset_and_verify_device(udev); } return status; } #endif static int hub_suspend(struct usb_interface *intf, pm_message_t msg) { struct usb_hub *hub = usb_get_intfdata (intf); struct usb_device *hdev = hub->hdev; unsigned port1; /* Warn if children aren't already suspended */ for (port1 = 1; port1 <= hdev->maxchild; port1++) { struct usb_device *udev; udev = hdev->children [port1-1]; if (udev && udev->can_submit) { dev_warn(&intf->dev, "port %d nyet suspended\n", port1); if (PMSG_IS_AUTO(msg)) return -EBUSY; } } dev_dbg(&intf->dev, "%s\n", __func__); /* stop khubd and related activity */ hub_quiesce(hub, HUB_SUSPEND); return 0; } static int hub_resume(struct usb_interface *intf) { struct usb_hub *hub = usb_get_intfdata(intf); dev_dbg(&intf->dev, "%s\n", __func__); hub_activate(hub, HUB_RESUME); return 0; } static int hub_reset_resume(struct usb_interface *intf) { struct usb_hub *hub = usb_get_intfdata(intf); dev_dbg(&intf->dev, "%s\n", __func__); hub_activate(hub, HUB_RESET_RESUME); return 0; } /** * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power * @rhdev: struct usb_device for the root hub * * The USB host controller driver calls this function when its root hub * is resumed and Vbus power has been interrupted or the controller * has been reset. The routine marks @rhdev as having lost power. * When the hub driver is resumed it will take notice and carry out * power-session recovery for all the "USB-PERSIST"-enabled child devices; * the others will be disconnected. */ void usb_root_hub_lost_power(struct usb_device *rhdev) { dev_warn(&rhdev->dev, "root hub lost power or was reset\n"); rhdev->reset_resume = 1; } EXPORT_SYMBOL_GPL(usb_root_hub_lost_power); #else /* CONFIG_PM */ #define hub_suspend NULL #define hub_resume NULL #define hub_reset_resume NULL #endif /* USB 2.0 spec, 7.1.7.3 / fig 7-29: * * Between connect detection and reset signaling there must be a delay * of 100ms at least for debounce and power-settling. The corresponding * timer shall restart whenever the downstream port detects a disconnect. * * Apparently there are some bluetooth and irda-dongles and a number of * low-speed devices for which this debounce period may last over a second. * Not covered by the spec - but easy to deal with. * * This implementation uses a 1500ms total debounce timeout; if the * connection isn't stable by then it returns -ETIMEDOUT. It checks * every 25ms for transient disconnects. When the port status has been * unchanged for 100ms it returns the port status. */ static int hub_port_debounce(struct usb_hub *hub, int port1) { int ret; int total_time, stable_time = 0; u16 portchange, portstatus; unsigned connection = 0xffff; for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) { ret = hub_port_status(hub, port1, &portstatus, &portchange); if (ret < 0) return ret; if (!(portchange & USB_PORT_STAT_C_CONNECTION) && (portstatus & USB_PORT_STAT_CONNECTION) == connection) { stable_time += HUB_DEBOUNCE_STEP; if (stable_time >= HUB_DEBOUNCE_STABLE) break; } else { stable_time = 0; connection = portstatus & USB_PORT_STAT_CONNECTION; } if (portchange & USB_PORT_STAT_C_CONNECTION) { clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_CONNECTION); } if (total_time >= HUB_DEBOUNCE_TIMEOUT) break; msleep(HUB_DEBOUNCE_STEP); } dev_dbg (hub->intfdev, "debounce: port %d: total %dms stable %dms status 0x%x\n", port1, total_time, stable_time, portstatus); if (stable_time < HUB_DEBOUNCE_STABLE) return -ETIMEDOUT; return portstatus; } void usb_ep0_reinit(struct usb_device *udev) { usb_disable_endpoint(udev, 0 + USB_DIR_IN, true); usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true); usb_enable_endpoint(udev, &udev->ep0, true); } EXPORT_SYMBOL_GPL(usb_ep0_reinit); #define usb_sndaddr0pipe() (PIPE_CONTROL << 30) #define usb_rcvaddr0pipe() ((PIPE_CONTROL << 30) | USB_DIR_IN) static int hub_set_address(struct usb_device *udev, int devnum) { int retval; struct usb_hcd *hcd = bus_to_hcd(udev->bus); /* * The host controller will choose the device address, * instead of the core having chosen it earlier */ if (!hcd->driver->address_device && devnum <= 1) return -EINVAL; if (udev->state == USB_STATE_ADDRESS) return 0; if (udev->state != USB_STATE_DEFAULT) return -EINVAL; if (hcd->driver->address_device) retval = hcd->driver->address_device(hcd, udev); else retval = usb_control_msg(udev, usb_sndaddr0pipe(), USB_REQ_SET_ADDRESS, 0, devnum, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (retval == 0) { update_devnum(udev, devnum); /* Device now using proper address. */ usb_set_device_state(udev, USB_STATE_ADDRESS); usb_ep0_reinit(udev); } return retval; } /* Reset device, (re)assign address, get device descriptor. * Device connection must be stable, no more debouncing needed. * Returns device in USB_STATE_ADDRESS, except on error. * * If this is called for an already-existing device (as part of * usb_reset_and_verify_device), the caller must own the device lock. For a * newly detected device that is not accessible through any global * pointers, it's not necessary to lock the device. */ static int hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1, int retry_counter) { static DEFINE_MUTEX(usb_address0_mutex); struct usb_device *hdev = hub->hdev; struct usb_hcd *hcd = bus_to_hcd(hdev->bus); int i, j, retval; unsigned delay = HUB_SHORT_RESET_TIME; enum usb_device_speed oldspeed = udev->speed; const char *speed; int devnum = udev->devnum; /* root hub ports have a slightly longer reset period * (from USB 2.0 spec, section 7.1.7.5) */ if (!hdev->parent) { delay = HUB_ROOT_RESET_TIME; if (port1 == hdev->bus->otg_port) hdev->bus->b_hnp_enable = 0; } /* Some low speed devices have problems with the quick delay, so */ /* be a bit pessimistic with those devices. RHbug #23670 */ if (oldspeed == USB_SPEED_LOW) delay = HUB_LONG_RESET_TIME; mutex_lock(&usb_address0_mutex); /* Reset the device; full speed may morph to high speed */ /* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */ retval = hub_port_reset(hub, port1, udev, delay, false); if (retval < 0) /* error or disconnect */ goto fail; /* success, speed is known */ retval = -ENODEV; if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) { dev_dbg(&udev->dev, "device reset changed speed!\n"); goto fail; } oldspeed = udev->speed; /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ... * it's fixed size except for full speed devices. * For Wireless USB devices, ep0 max packet is always 512 (tho * reported as 0xff in the device descriptor). WUSB1.0[4.8.1]. */ switch (udev->speed) { case USB_SPEED_SUPER: case USB_SPEED_WIRELESS: /* fixed at 512 */ udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512); break; case USB_SPEED_HIGH: /* fixed at 64 */ udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64); break; case USB_SPEED_FULL: /* 8, 16, 32, or 64 */ /* to determine the ep0 maxpacket size, try to read * the device descriptor to get bMaxPacketSize0 and * then correct our initial guess. */ udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64); break; case USB_SPEED_LOW: /* fixed at 8 */ udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8); break; default: goto fail; } if (udev->speed == USB_SPEED_WIRELESS) speed = "variable speed Wireless"; else speed = usb_speed_string(udev->speed); if (udev->speed != USB_SPEED_SUPER) dev_info(&udev->dev, "%s %s USB device number %d using %s\n", (udev->config) ? "reset" : "new", speed, devnum, udev->bus->controller->driver->name); /* Set up TT records, if needed */ if (hdev->tt) { udev->tt = hdev->tt; udev->ttport = hdev->ttport; } else if (udev->speed != USB_SPEED_HIGH && hdev->speed == USB_SPEED_HIGH) { if (!hub->tt.hub) { dev_err(&udev->dev, "parent hub has no TT\n"); retval = -EINVAL; goto fail; } udev->tt = &hub->tt; udev->ttport = port1; } /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way? * Because device hardware and firmware is sometimes buggy in * this area, and this is how Linux has done it for ages. * Change it cautiously. * * NOTE: If USE_NEW_SCHEME() is true we will start by issuing * a 64-byte GET_DESCRIPTOR request. This is what Windows does, * so it may help with some non-standards-compliant devices. * Otherwise we start with SET_ADDRESS and then try to read the * first 8 bytes of the device descriptor to get the ep0 maxpacket * value. */ for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) { if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) { struct usb_device_descriptor *buf; int r = 0; #define GET_DESCRIPTOR_BUFSIZE 64 buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO); if (!buf) { retval = -ENOMEM; continue; } /* Retry on all errors; some devices are flakey. * 255 is for WUSB devices, we actually need to use * 512 (WUSB1.0[4.8.1]). */ for (j = 0; j < 3; ++j) { buf->bMaxPacketSize0 = 0; r = usb_control_msg(udev, usb_rcvaddr0pipe(), USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, USB_DT_DEVICE << 8, 0, buf, GET_DESCRIPTOR_BUFSIZE, initial_descriptor_timeout); switch (buf->bMaxPacketSize0) { case 8: case 16: case 32: case 64: case 255: if (buf->bDescriptorType == USB_DT_DEVICE) { r = 0; break; } /* FALL THROUGH */ default: if (r == 0) r = -EPROTO; break; } if (r == 0) break; } udev->descriptor.bMaxPacketSize0 = buf->bMaxPacketSize0; kfree(buf); retval = hub_port_reset(hub, port1, udev, delay, false); if (retval < 0) /* error or disconnect */ goto fail; if (oldspeed != udev->speed) { dev_dbg(&udev->dev, "device reset changed speed!\n"); retval = -ENODEV; goto fail; } if (r) { dev_err(&udev->dev, "device descriptor read/64, error %d\n", r); retval = -EMSGSIZE; continue; } #undef GET_DESCRIPTOR_BUFSIZE } /* * If device is WUSB, we already assigned an * unauthorized address in the Connect Ack sequence; * authorization will assign the final address. */ if (udev->wusb == 0) { for (j = 0; j < SET_ADDRESS_TRIES; ++j) { retval = hub_set_address(udev, devnum); if (retval >= 0) break; msleep(200); } if (retval < 0) { dev_err(&udev->dev, "device not accepting address %d, error %d\n", devnum, retval); goto fail; } if (udev->speed == USB_SPEED_SUPER) { devnum = udev->devnum; dev_info(&udev->dev, "%s SuperSpeed USB device number %d using %s\n", (udev->config) ? "reset" : "new", devnum, udev->bus->controller->driver->name); } /* cope with hardware quirkiness: * - let SET_ADDRESS settle, some device hardware wants it * - read ep0 maxpacket even for high and low speed, */ msleep(10); if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) break; } retval = usb_get_device_descriptor(udev, 8); if (retval < 8) { dev_err(&udev->dev, "device descriptor read/8, error %d\n", retval); if (retval >= 0) retval = -EMSGSIZE; } else { retval = 0; break; } } if (retval) goto fail; if (udev->descriptor.bMaxPacketSize0 == 0xff || udev->speed == USB_SPEED_SUPER) i = 512; else i = udev->descriptor.bMaxPacketSize0; if (usb_endpoint_maxp(&udev->ep0.desc) != i) { if (udev->speed == USB_SPEED_LOW || !(i == 8 || i == 16 || i == 32 || i == 64)) { dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i); retval = -EMSGSIZE; goto fail; } if (udev->speed == USB_SPEED_FULL) dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i); else dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i); udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i); usb_ep0_reinit(udev); } retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE); if (retval < (signed)sizeof(udev->descriptor)) { dev_err(&udev->dev, "device descriptor read/all, error %d\n", retval); if (retval >= 0) retval = -ENOMSG; goto fail; } if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) { retval = usb_get_bos_descriptor(udev); if (!retval) { if (udev->bos->ext_cap && (USB_LPM_SUPPORT & le32_to_cpu(udev->bos->ext_cap->bmAttributes))) udev->lpm_capable = 1; } } retval = 0; /* notify HCD that we have a device connected and addressed */ if (hcd->driver->update_device) hcd->driver->update_device(hcd, udev); fail: if (retval) { hub_port_disable(hub, port1, 0); update_devnum(udev, devnum); /* for disconnect processing */ } mutex_unlock(&usb_address0_mutex); return retval; } static void check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1) { struct usb_qualifier_descriptor *qual; int status; qual = kmalloc (sizeof *qual, GFP_KERNEL); if (qual == NULL) return; status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0, qual, sizeof *qual); if (status == sizeof *qual) { dev_info(&udev->dev, "not running at top speed; " "connect to a high speed hub\n"); /* hub LEDs are probably harder to miss than syslog */ if (hub->has_indicators) { hub->indicator[port1-1] = INDICATOR_GREEN_BLINK; schedule_delayed_work (&hub->leds, 0); } } kfree(qual); } static unsigned hub_power_remaining (struct usb_hub *hub) { struct usb_device *hdev = hub->hdev; int remaining; int port1; if (!hub->limited_power) return 0; remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent; for (port1 = 1; port1 <= hdev->maxchild; ++port1) { struct usb_device *udev = hdev->children[port1 - 1]; int delta; if (!udev) continue; /* Unconfigured devices may not use more than 100mA, * or 8mA for OTG ports */ if (udev->actconfig) delta = udev->actconfig->desc.bMaxPower * 2; else if (port1 != udev->bus->otg_port || hdev->parent) delta = 100; else delta = 8; if (delta > hub->mA_per_port) dev_warn(&udev->dev, "%dmA is over %umA budget for port %d!\n", delta, hub->mA_per_port, port1); remaining -= delta; } if (remaining < 0) { dev_warn(hub->intfdev, "%dmA over power budget!\n", - remaining); remaining = 0; } return remaining; } /* Handle physical or logical connection change events. * This routine is called when: * a port connection-change occurs; * a port enable-change occurs (often caused by EMI); * usb_reset_and_verify_device() encounters changed descriptors (as from * a firmware download) * caller already locked the hub */ static void hub_port_connect_change(struct usb_hub *hub, int port1, u16 portstatus, u16 portchange) { struct usb_device *hdev = hub->hdev; struct device *hub_dev = hub->intfdev; struct usb_hcd *hcd = bus_to_hcd(hdev->bus); unsigned wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics); struct usb_device *udev; int status, i; dev_dbg (hub_dev, "port %d, status %04x, change %04x, %s\n", port1, portstatus, portchange, portspeed(hub, portstatus)); if (hub->has_indicators) { set_port_led(hub, port1, HUB_LED_AUTO); hub->indicator[port1-1] = INDICATOR_AUTO; } #ifdef CONFIG_USB_OTG /* during HNP, don't repeat the debounce */ if (hdev->bus->is_b_host) portchange &= ~(USB_PORT_STAT_C_CONNECTION | USB_PORT_STAT_C_ENABLE); #endif /* Try to resuscitate an existing device */ udev = hdev->children[port1-1]; if ((portstatus & USB_PORT_STAT_CONNECTION) && udev && udev->state != USB_STATE_NOTATTACHED) { usb_lock_device(udev); if (portstatus & USB_PORT_STAT_ENABLE) { status = 0; /* Nothing to do */ #ifdef CONFIG_USB_SUSPEND } else if (udev->state == USB_STATE_SUSPENDED && udev->persist_enabled) { /* For a suspended device, treat this as a * remote wakeup event. */ status = usb_remote_wakeup(udev); #endif } else { status = -ENODEV; /* Don't resuscitate */ } usb_unlock_device(udev); if (status == 0) { clear_bit(port1, hub->change_bits); return; } } /* Disconnect any existing devices under this port */ if (udev) usb_disconnect(&hdev->children[port1-1]); clear_bit(port1, hub->change_bits); /* We can forget about a "removed" device when there's a physical * disconnect or the connect status changes. */ if (!(portstatus & USB_PORT_STAT_CONNECTION) || (portchange & USB_PORT_STAT_C_CONNECTION)) clear_bit(port1, hub->removed_bits); if (portchange & (USB_PORT_STAT_C_CONNECTION | USB_PORT_STAT_C_ENABLE)) { status = hub_port_debounce(hub, port1); if (status < 0) { if (printk_ratelimit()) dev_err(hub_dev, "connect-debounce failed, " "port %d disabled\n", port1); portstatus &= ~USB_PORT_STAT_CONNECTION; } else { portstatus = status; } } /* Return now if debouncing failed or nothing is connected or * the device was "removed". */ if (!(portstatus & USB_PORT_STAT_CONNECTION) || test_bit(port1, hub->removed_bits)) { /* maybe switch power back on (e.g. root hub was reset) */ if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2 && !port_is_power_on(hub, portstatus)) set_port_feature(hdev, port1, USB_PORT_FEAT_POWER); if (portstatus & USB_PORT_STAT_ENABLE) goto done; return; } for (i = 0; i < SET_CONFIG_TRIES; i++) { /* reallocate for each attempt, since references * to the previous one can escape in various ways */ udev = usb_alloc_dev(hdev, hdev->bus, port1); if (!udev) { dev_err (hub_dev, "couldn't allocate port %d usb_device\n", port1); goto done; } usb_set_device_state(udev, USB_STATE_POWERED); udev->bus_mA = hub->mA_per_port; udev->level = hdev->level + 1; udev->wusb = hub_is_wusb(hub); /* Only USB 3.0 devices are connected to SuperSpeed hubs. */ if (hub_is_superspeed(hub->hdev)) udev->speed = USB_SPEED_SUPER; else udev->speed = USB_SPEED_UNKNOWN; choose_devnum(udev); if (udev->devnum <= 0) { status = -ENOTCONN; /* Don't retry */ goto loop; } /* reset (non-USB 3.0 devices) and get descriptor */ status = hub_port_init(hub, udev, port1, i); if (status < 0) goto loop; usb_detect_quirks(udev); if (udev->quirks & USB_QUIRK_DELAY_INIT) msleep(1000); /* consecutive bus-powered hubs aren't reliable; they can * violate the voltage drop budget. if the new child has * a "powered" LED, users should notice we didn't enable it * (without reading syslog), even without per-port LEDs * on the parent. */ if (udev->descriptor.bDeviceClass == USB_CLASS_HUB && udev->bus_mA <= 100) { u16 devstat; status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstat); if (status < 2) { dev_dbg(&udev->dev, "get status %d ?\n", status); goto loop_disable; } le16_to_cpus(&devstat); if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) { dev_err(&udev->dev, "can't connect bus-powered hub " "to this port\n"); if (hub->has_indicators) { hub->indicator[port1-1] = INDICATOR_AMBER_BLINK; schedule_delayed_work (&hub->leds, 0); } status = -ENOTCONN; /* Don't retry */ goto loop_disable; } } /* check for devices running slower than they could */ if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200 && udev->speed == USB_SPEED_FULL && highspeed_hubs != 0) check_highspeed (hub, udev, port1); /* Store the parent's children[] pointer. At this point * udev becomes globally accessible, although presumably * no one will look at it until hdev is unlocked. */ status = 0; /* We mustn't add new devices if the parent hub has * been disconnected; we would race with the * recursively_mark_NOTATTACHED() routine. */ spin_lock_irq(&device_state_lock); if (hdev->state == USB_STATE_NOTATTACHED) status = -ENOTCONN; else hdev->children[port1-1] = udev; spin_unlock_irq(&device_state_lock); /* Run it through the hoops (find a driver, etc) */ if (!status) { status = usb_new_device(udev); if (status) { spin_lock_irq(&device_state_lock); hdev->children[port1-1] = NULL; spin_unlock_irq(&device_state_lock); } } if (status) goto loop_disable; status = hub_power_remaining(hub); if (status) dev_dbg(hub_dev, "%dmA power budget left\n", status); return; loop_disable: hub_port_disable(hub, port1, 1); loop: usb_ep0_reinit(udev); release_devnum(udev); hub_free_dev(udev); usb_put_dev(udev); if ((status == -ENOTCONN) || (status == -ENOTSUPP)) break; } if (hub->hdev->parent || !hcd->driver->port_handed_over || !(hcd->driver->port_handed_over)(hcd, port1)) dev_err(hub_dev, "unable to enumerate USB device on port %d\n", port1); done: hub_port_disable(hub, port1, 1); if (hcd->driver->relinquish_port && !hub->hdev->parent) hcd->driver->relinquish_port(hcd, port1); } static void hub_events(void) { struct list_head *tmp; struct usb_device *hdev; struct usb_interface *intf; struct usb_hub *hub; struct device *hub_dev; u16 hubstatus; u16 hubchange; u16 portstatus; u16 portchange; int i, ret; int connect_change; /* * We restart the list every time to avoid a deadlock with * deleting hubs downstream from this one. This should be * safe since we delete the hub from the event list. * Not the most efficient, but avoids deadlocks. */ while (1) { /* Grab the first entry at the beginning of the list */ spin_lock_irq(&hub_event_lock); if (list_empty(&hub_event_list)) { spin_unlock_irq(&hub_event_lock); break; } tmp = hub_event_list.next; list_del_init(tmp); hub = list_entry(tmp, struct usb_hub, event_list); kref_get(&hub->kref); spin_unlock_irq(&hub_event_lock); hdev = hub->hdev; hub_dev = hub->intfdev; intf = to_usb_interface(hub_dev); dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n", hdev->state, hub->descriptor ? hub->descriptor->bNbrPorts : 0, /* NOTE: expects max 15 ports... */ (u16) hub->change_bits[0], (u16) hub->event_bits[0]); /* Lock the device, then check to see if we were * disconnected while waiting for the lock to succeed. */ usb_lock_device(hdev); if (unlikely(hub->disconnected)) goto loop_disconnected; /* If the hub has died, clean up after it */ if (hdev->state == USB_STATE_NOTATTACHED) { hub->error = -ENODEV; hub_quiesce(hub, HUB_DISCONNECT); goto loop; } /* Autoresume */ ret = usb_autopm_get_interface(intf); if (ret) { dev_dbg(hub_dev, "Can't autoresume: %d\n", ret); goto loop; } /* If this is an inactive hub, do nothing */ if (hub->quiescing) goto loop_autopm; if (hub->error) { dev_dbg (hub_dev, "resetting for error %d\n", hub->error); ret = usb_reset_device(hdev); if (ret) { dev_dbg (hub_dev, "error resetting hub: %d\n", ret); goto loop_autopm; } hub->nerrors = 0; hub->error = 0; } /* deal with port status changes */ for (i = 1; i <= hub->descriptor->bNbrPorts; i++) { if (test_bit(i, hub->busy_bits)) continue; connect_change = test_bit(i, hub->change_bits); if (!test_and_clear_bit(i, hub->event_bits) && !connect_change) continue; ret = hub_port_status(hub, i, &portstatus, &portchange); if (ret < 0) continue; if (portchange & USB_PORT_STAT_C_CONNECTION) { clear_port_feature(hdev, i, USB_PORT_FEAT_C_CONNECTION); connect_change = 1; } if (portchange & USB_PORT_STAT_C_ENABLE) { if (!connect_change) dev_dbg (hub_dev, "port %d enable change, " "status %08x\n", i, portstatus); clear_port_feature(hdev, i, USB_PORT_FEAT_C_ENABLE); /* * EM interference sometimes causes badly * shielded USB devices to be shutdown by * the hub, this hack enables them again. * Works at least with mouse driver. */ if (!(portstatus & USB_PORT_STAT_ENABLE) && !connect_change && hdev->children[i-1]) { dev_err (hub_dev, "port %i " "disabled by hub (EMI?), " "re-enabling...\n", i); connect_change = 1; } } if (portchange & USB_PORT_STAT_C_SUSPEND) { struct usb_device *udev; clear_port_feature(hdev, i, USB_PORT_FEAT_C_SUSPEND); udev = hdev->children[i-1]; if (udev) { /* TRSMRCY = 10 msec */ msleep(10); usb_lock_device(udev); ret = usb_remote_wakeup(hdev-> children[i-1]); usb_unlock_device(udev); if (ret < 0) connect_change = 1; } else { ret = -ENODEV; hub_port_disable(hub, i, 1); } dev_dbg (hub_dev, "resume on port %d, status %d\n", i, ret); } if (portchange & USB_PORT_STAT_C_OVERCURRENT) { u16 status = 0; u16 unused; dev_dbg(hub_dev, "over-current change on port " "%d\n", i); clear_port_feature(hdev, i, USB_PORT_FEAT_C_OVER_CURRENT); msleep(100); /* Cool down */ hub_power_on(hub, true); hub_port_status(hub, i, &status, &unused); if (status & USB_PORT_STAT_OVERCURRENT) dev_err(hub_dev, "over-current " "condition on port %d\n", i); } if (portchange & USB_PORT_STAT_C_RESET) { dev_dbg (hub_dev, "reset change on port %d\n", i); clear_port_feature(hdev, i, USB_PORT_FEAT_C_RESET); } if ((portchange & USB_PORT_STAT_C_BH_RESET) && hub_is_superspeed(hub->hdev)) { dev_dbg(hub_dev, "warm reset change on port %d\n", i); clear_port_feature(hdev, i, USB_PORT_FEAT_C_BH_PORT_RESET); } if (portchange & USB_PORT_STAT_C_LINK_STATE) { clear_port_feature(hub->hdev, i, USB_PORT_FEAT_C_PORT_LINK_STATE); } if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) { dev_warn(hub_dev, "config error on port %d\n", i); clear_port_feature(hub->hdev, i, USB_PORT_FEAT_C_PORT_CONFIG_ERROR); } /* Warm reset a USB3 protocol port if it's in * SS.Inactive state. */ if (hub_is_superspeed(hub->hdev) && (portstatus & USB_PORT_STAT_LINK_STATE) == USB_SS_PORT_LS_SS_INACTIVE) { dev_dbg(hub_dev, "warm reset port %d\n", i); hub_port_reset(hub, i, NULL, HUB_BH_RESET_TIME, true); } if (connect_change) hub_port_connect_change(hub, i, portstatus, portchange); } /* end for i */ /* deal with hub status changes */ if (test_and_clear_bit(0, hub->event_bits) == 0) ; /* do nothing */ else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0) dev_err (hub_dev, "get_hub_status failed\n"); else { if (hubchange & HUB_CHANGE_LOCAL_POWER) { dev_dbg (hub_dev, "power change\n"); clear_hub_feature(hdev, C_HUB_LOCAL_POWER); if (hubstatus & HUB_STATUS_LOCAL_POWER) /* FIXME: Is this always true? */ hub->limited_power = 1; else hub->limited_power = 0; } if (hubchange & HUB_CHANGE_OVERCURRENT) { u16 status = 0; u16 unused; dev_dbg(hub_dev, "over-current change\n"); clear_hub_feature(hdev, C_HUB_OVER_CURRENT); msleep(500); /* Cool down */ hub_power_on(hub, true); hub_hub_status(hub, &status, &unused); if (status & HUB_STATUS_OVERCURRENT) dev_err(hub_dev, "over-current " "condition\n"); } } loop_autopm: /* Balance the usb_autopm_get_interface() above */ usb_autopm_put_interface_no_suspend(intf); loop: /* Balance the usb_autopm_get_interface_no_resume() in * kick_khubd() and allow autosuspend. */ usb_autopm_put_interface(intf); loop_disconnected: usb_unlock_device(hdev); kref_put(&hub->kref, hub_release); } /* end while (1) */ } static int hub_thread(void *__unused) { /* khubd needs to be freezable to avoid intefering with USB-PERSIST * port handover. Otherwise it might see that a full-speed device * was gone before the EHCI controller had handed its port over to * the companion full-speed controller. */ set_freezable(); do { hub_events(); wait_event_freezable(khubd_wait, !list_empty(&hub_event_list) || kthread_should_stop()); } while (!kthread_should_stop() || !list_empty(&hub_event_list)); pr_debug("%s: khubd exiting\n", usbcore_name); return 0; } static const struct usb_device_id hub_id_table[] = { { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS, .bDeviceClass = USB_CLASS_HUB}, { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS, .bInterfaceClass = USB_CLASS_HUB}, { } /* Terminating entry */ }; MODULE_DEVICE_TABLE (usb, hub_id_table); static struct usb_driver hub_driver = { .name = "hub", .probe = hub_probe, .disconnect = hub_disconnect, .suspend = hub_suspend, .resume = hub_resume, .reset_resume = hub_reset_resume, .pre_reset = hub_pre_reset, .post_reset = hub_post_reset, .unlocked_ioctl = hub_ioctl, .id_table = hub_id_table, .supports_autosuspend = 1, }; int usb_hub_init(void) { if (usb_register(&hub_driver) < 0) { printk(KERN_ERR "%s: can't register hub driver\n", usbcore_name); return -1; } khubd_task = kthread_run(hub_thread, NULL, "khubd"); if (!IS_ERR(khubd_task)) return 0; /* Fall through if kernel_thread failed */ usb_deregister(&hub_driver); printk(KERN_ERR "%s: can't start khubd\n", usbcore_name); return -1; } void usb_hub_cleanup(void) { kthread_stop(khubd_task); /* * Hub resources are freed for us by usb_deregister. It calls * usb_driver_purge on every device which in turn calls that * devices disconnect function if it is using this driver. * The hub_disconnect function takes care of releasing the * individual hub resources. -greg */ usb_deregister(&hub_driver); } /* usb_hub_cleanup() */ static int descriptors_changed(struct usb_device *udev, struct usb_device_descriptor *old_device_descriptor) { int changed = 0; unsigned index; unsigned serial_len = 0; unsigned len; unsigned old_length; int length; char *buf; if (memcmp(&udev->descriptor, old_device_descriptor, sizeof(*old_device_descriptor)) != 0) return 1; /* Since the idVendor, idProduct, and bcdDevice values in the * device descriptor haven't changed, we will assume the * Manufacturer and Product strings haven't changed either. * But the SerialNumber string could be different (e.g., a * different flash card of the same brand). */ if (udev->serial) serial_len = strlen(udev->serial) + 1; len = serial_len; for (index = 0; index < udev->descriptor.bNumConfigurations; index++) { old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); len = max(len, old_length); } buf = kmalloc(len, GFP_NOIO); if (buf == NULL) { dev_err(&udev->dev, "no mem to re-read configs after reset\n"); /* assume the worst */ return 1; } for (index = 0; index < udev->descriptor.bNumConfigurations; index++) { old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf, old_length); if (length != old_length) { dev_dbg(&udev->dev, "config index %d, error %d\n", index, length); changed = 1; break; } if (memcmp (buf, udev->rawdescriptors[index], old_length) != 0) { dev_dbg(&udev->dev, "config index %d changed (#%d)\n", index, ((struct usb_config_descriptor *) buf)-> bConfigurationValue); changed = 1; break; } } if (!changed && serial_len) { length = usb_string(udev, udev->descriptor.iSerialNumber, buf, serial_len); if (length + 1 != serial_len) { dev_dbg(&udev->dev, "serial string error %d\n", length); changed = 1; } else if (memcmp(buf, udev->serial, length) != 0) { dev_dbg(&udev->dev, "serial string changed\n"); changed = 1; } } kfree(buf); return changed; } /** * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device * @udev: device to reset (not in SUSPENDED or NOTATTACHED state) * * WARNING - don't use this routine to reset a composite device * (one with multiple interfaces owned by separate drivers)! * Use usb_reset_device() instead. * * Do a port reset, reassign the device's address, and establish its * former operating configuration. If the reset fails, or the device's * descriptors change from their values before the reset, or the original * configuration and altsettings cannot be restored, a flag will be set * telling khubd to pretend the device has been disconnected and then * re-connected. All drivers will be unbound, and the device will be * re-enumerated and probed all over again. * * Returns 0 if the reset succeeded, -ENODEV if the device has been * flagged for logical disconnection, or some other negative error code * if the reset wasn't even attempted. * * The caller must own the device lock. For example, it's safe to use * this from a driver probe() routine after downloading new firmware. * For calls that might not occur during probe(), drivers should lock * the device using usb_lock_device_for_reset(). * * Locking exception: This routine may also be called from within an * autoresume handler. Such usage won't conflict with other tasks * holding the device lock because these tasks should always call * usb_autopm_resume_device(), thereby preventing any unwanted autoresume. */ static int usb_reset_and_verify_device(struct usb_device *udev) { struct usb_device *parent_hdev = udev->parent; struct usb_hub *parent_hub; struct usb_hcd *hcd = bus_to_hcd(udev->bus); struct usb_device_descriptor descriptor = udev->descriptor; int i, ret = 0; int port1 = udev->portnum; if (udev->state == USB_STATE_NOTATTACHED || udev->state == USB_STATE_SUSPENDED) { dev_dbg(&udev->dev, "device reset not allowed in state %d\n", udev->state); return -EINVAL; } if (!parent_hdev) { /* this requires hcd-specific logic; see ohci_restart() */ dev_dbg(&udev->dev, "%s for root hub!\n", __func__); return -EISDIR; } parent_hub = hdev_to_hub(parent_hdev); set_bit(port1, parent_hub->busy_bits); for (i = 0; i < SET_CONFIG_TRIES; ++i) { /* ep0 maxpacket size may change; let the HCD know about it. * Other endpoints will be handled by re-enumeration. */ usb_ep0_reinit(udev); ret = hub_port_init(parent_hub, udev, port1, i); if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV) break; } clear_bit(port1, parent_hub->busy_bits); if (ret < 0) goto re_enumerate; /* Device might have changed firmware (DFU or similar) */ if (descriptors_changed(udev, &descriptor)) { dev_info(&udev->dev, "device firmware changed\n"); udev->descriptor = descriptor; /* for disconnect() calls */ goto re_enumerate; } /* Restore the device's previous configuration */ if (!udev->actconfig) goto done; mutex_lock(hcd->bandwidth_mutex); ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL); if (ret < 0) { dev_warn(&udev->dev, "Busted HC? Not enough HCD resources for " "old configuration.\n"); mutex_unlock(hcd->bandwidth_mutex); goto re_enumerate; } ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), USB_REQ_SET_CONFIGURATION, 0, udev->actconfig->desc.bConfigurationValue, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (ret < 0) { dev_err(&udev->dev, "can't restore configuration #%d (error=%d)\n", udev->actconfig->desc.bConfigurationValue, ret); mutex_unlock(hcd->bandwidth_mutex); goto re_enumerate; } mutex_unlock(hcd->bandwidth_mutex); usb_set_device_state(udev, USB_STATE_CONFIGURED); /* Put interfaces back into the same altsettings as before. * Don't bother to send the Set-Interface request for interfaces * that were already in altsetting 0; besides being unnecessary, * many devices can't handle it. Instead just reset the host-side * endpoint state. */ for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { struct usb_host_config *config = udev->actconfig; struct usb_interface *intf = config->interface[i]; struct usb_interface_descriptor *desc; desc = &intf->cur_altsetting->desc; if (desc->bAlternateSetting == 0) { usb_disable_interface(udev, intf, true); usb_enable_interface(udev, intf, true); ret = 0; } else { /* Let the bandwidth allocation function know that this * device has been reset, and it will have to use * alternate setting 0 as the current alternate setting. */ intf->resetting_device = 1; ret = usb_set_interface(udev, desc->bInterfaceNumber, desc->bAlternateSetting); intf->resetting_device = 0; } if (ret < 0) { dev_err(&udev->dev, "failed to restore interface %d " "altsetting %d (error=%d)\n", desc->bInterfaceNumber, desc->bAlternateSetting, ret); goto re_enumerate; } } done: return 0; re_enumerate: hub_port_logical_disconnect(parent_hub, port1); return -ENODEV; } /** * usb_reset_device - warn interface drivers and perform a USB port reset * @udev: device to reset (not in SUSPENDED or NOTATTACHED state) * * Warns all drivers bound to registered interfaces (using their pre_reset * method), performs the port reset, and then lets the drivers know that * the reset is over (using their post_reset method). * * Return value is the same as for usb_reset_and_verify_device(). * * The caller must own the device lock. For example, it's safe to use * this from a driver probe() routine after downloading new firmware. * For calls that might not occur during probe(), drivers should lock * the device using usb_lock_device_for_reset(). * * If an interface is currently being probed or disconnected, we assume * its driver knows how to handle resets. For all other interfaces, * if the driver doesn't have pre_reset and post_reset methods then * we attempt to unbind it and rebind afterward. */ int usb_reset_device(struct usb_device *udev) { int ret; int i; struct usb_host_config *config = udev->actconfig; if (udev->state == USB_STATE_NOTATTACHED || udev->state == USB_STATE_SUSPENDED) { dev_dbg(&udev->dev, "device reset not allowed in state %d\n", udev->state); return -EINVAL; } /* Prevent autosuspend during the reset */ usb_autoresume_device(udev); if (config) { for (i = 0; i < config->desc.bNumInterfaces; ++i) { struct usb_interface *cintf = config->interface[i]; struct usb_driver *drv; int unbind = 0; if (cintf->dev.driver) { drv = to_usb_driver(cintf->dev.driver); if (drv->pre_reset && drv->post_reset) unbind = (drv->pre_reset)(cintf); else if (cintf->condition == USB_INTERFACE_BOUND) unbind = 1; if (unbind) usb_forced_unbind_intf(cintf); } } } ret = usb_reset_and_verify_device(udev); if (config) { for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) { struct usb_interface *cintf = config->interface[i]; struct usb_driver *drv; int rebind = cintf->needs_binding; if (!rebind && cintf->dev.driver) { drv = to_usb_driver(cintf->dev.driver); if (drv->post_reset) rebind = (drv->post_reset)(cintf); else if (cintf->condition == USB_INTERFACE_BOUND) rebind = 1; } if (ret == 0 && rebind) usb_rebind_intf(cintf); } } usb_autosuspend_device(udev); return ret; } EXPORT_SYMBOL_GPL(usb_reset_device); /** * usb_queue_reset_device - Reset a USB device from an atomic context * @iface: USB interface belonging to the device to reset * * This function can be used to reset a USB device from an atomic * context, where usb_reset_device() won't work (as it blocks). * * Doing a reset via this method is functionally equivalent to calling * usb_reset_device(), except for the fact that it is delayed to a * workqueue. This means that any drivers bound to other interfaces * might be unbound, as well as users from usbfs in user space. * * Corner cases: * * - Scheduling two resets at the same time from two different drivers * attached to two different interfaces of the same device is * possible; depending on how the driver attached to each interface * handles ->pre_reset(), the second reset might happen or not. * * - If a driver is unbound and it had a pending reset, the reset will * be cancelled. * * - This function can be called during .probe() or .disconnect() * times. On return from .disconnect(), any pending resets will be * cancelled. * * There is no no need to lock/unlock the @reset_ws as schedule_work() * does its own. * * NOTE: We don't do any reference count tracking because it is not * needed. The lifecycle of the work_struct is tied to the * usb_interface. Before destroying the interface we cancel the * work_struct, so the fact that work_struct is queued and or * running means the interface (and thus, the device) exist and * are referenced. */ void usb_queue_reset_device(struct usb_interface *iface) { schedule_work(&iface->reset_ws); } EXPORT_SYMBOL_GPL(usb_queue_reset_device);