diff options
| author | Oliver Neukum <oliver@neukum.org> | 2010-02-27 20:54:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-03-19 07:24:15 -0700 |
| commit | 922a5eadd5a3aa0b806be0c18694b618d41d0784 (patch) | |
| tree | 25d6a630e5bd92ff0c900d94125481f53e9b377a | |
| parent | 860e41a71c1731e79e1920dc42676bafc925af5e (diff) | |
usb: cdc-wdm: Fix race between autosuspend and reading from the device
While an available response is read the device must not
be autosuspended. This requires a flag dedicated to that
purpose.
Signed-off-by: Oliver Neukum <neukum@b1-systems.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/class/cdc-wdm.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index cf1c5fb918dc..940b17af162c 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -52,6 +52,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_READ 4 #define WDM_INT_STALL 5 #define WDM_POLL_RUNNING 6 +#define WDM_RESPONDING 7 #define WDM_MAX 16 @@ -115,21 +116,22 @@ static void wdm_in_callback(struct urb *urb) int status = urb->status; spin_lock(&desc->iuspin); + clear_bit(WDM_RESPONDING, &desc->flags); if (status) { switch (status) { case -ENOENT: dev_dbg(&desc->intf->dev, "nonzero urb status received: -ENOENT"); - break; + goto skip_error; case -ECONNRESET: dev_dbg(&desc->intf->dev, "nonzero urb status received: -ECONNRESET"); - break; + goto skip_error; case -ESHUTDOWN: dev_dbg(&desc->intf->dev, "nonzero urb status received: -ESHUTDOWN"); - break; + goto skip_error; case -EPIPE: dev_err(&desc->intf->dev, "nonzero urb status received: -EPIPE\n"); @@ -145,6 +147,7 @@ static void wdm_in_callback(struct urb *urb) desc->reslength = urb->actual_length; memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength); desc->length += desc->reslength; +skip_error: wake_up(&desc->wait); set_bit(WDM_READ, &desc->flags); @@ -227,6 +230,7 @@ static void wdm_int_callback(struct urb *urb) desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; spin_lock(&desc->iuspin); clear_bit(WDM_READ, &desc->flags); + set_bit(WDM_RESPONDING, &desc->flags); if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { rv = usb_submit_urb(desc->response, GFP_ATOMIC); dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", @@ -234,6 +238,7 @@ static void wdm_int_callback(struct urb *urb) } spin_unlock(&desc->iuspin); if (rv < 0) { + clear_bit(WDM_RESPONDING, &desc->flags); if (rv == -EPERM) return; if (rv == -ENOMEM) { @@ -795,7 +800,8 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message) mutex_lock(&desc->lock); #ifdef CONFIG_PM if ((message.event & PM_EVENT_AUTO) && - test_bit(WDM_IN_USE, &desc->flags)) { + (test_bit(WDM_IN_USE, &desc->flags) + || test_bit(WDM_RESPONDING, &desc->flags))) { rv = -EBUSY; } else { #endif |