diff options
author | Hans Petter Selasky <hans.petter.selasky@stericsson.com> | 2010-08-13 14:14:54 +0200 |
---|---|---|
committer | Philippe Langlais <philippe.langlais@linaro.org> | 2011-07-22 15:40:44 +0200 |
commit | bac67b6b0b6bccd92c70dc6baa506fee8d2acb5a (patch) | |
tree | f81b96911d6e0c714df2052b86294fbe7feccbb8 | |
parent | 096f9efb80392662b61891ae7657279f69a4cb74 (diff) |
Workaround for hardware problem in host mode for the MUSB chipset. Add missed TXPKTRDY check.
FIFOFLUSH is broken when a real packet is in the FIFO. This
hardware feature only works when the FIFO is empty.
The workaround described requires limiting the maximum
number of USB devices to 126, 128 - 2.
Signed-off-by: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
Signed-off-by: Praveena Nadahally <praveen.nadahally@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
-rw-r--r-- | drivers/usb/core/hub.c | 8 | ||||
-rw-r--r-- | drivers/usb/musb/musb_host.c | 45 |
2 files changed, 37 insertions, 16 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index a428aa080a3..72150c7ea3a 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1579,12 +1579,14 @@ static void choose_devnum(struct usb_device *udev) * bus->devnum_next. */ devnum = find_next_zero_bit(bus->devmap.devicemap, 128, bus->devnum_next); - if (devnum >= 128) + /* Due to Hardware bugs we need to reserve a device address + * for flushing of endpoints. */ + if (devnum >= 127) devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1); - bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1); + bus->devnum_next = devnum >= 126 ? 1 : devnum + 1; } - if (devnum < 128) { + if (devnum < 127) { set_bit(devnum, bus->devmap.devicemap); udev->devnum = devnum; } diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index fbed2b34892..bafe726ef2a 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -108,24 +108,41 @@ static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep) { struct musb *musb = ep->musb; void __iomem *epio = ep->regs; + void __iomem *regs = ep->musb->mregs; u16 csr; - u16 lastcsr = 0; - int retries = 1000; + u8 addr; + int retries = 3000; /* 3ms */ + /* + * NOTE: We are using a hack here because the FIFO-FLUSH + * bit is broken in hardware! The hack consists of changing + * the TXFUNCADDR to an unused device address and waiting + * for any pending USB packets to hit the 3-strikes and your + * gone rule. + */ + addr = musb_readb(regs, MUSB_BUSCTL_OFFSET(ep->epnum, MUSB_TXFUNCADDR)); csr = musb_readw(epio, MUSB_TXCSR); while (csr & MUSB_TXCSR_FIFONOTEMPTY) { - if (csr != lastcsr) - dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr); - lastcsr = csr; - csr |= MUSB_TXCSR_FLUSHFIFO; - musb_writew(epio, MUSB_TXCSR, csr); + musb_writeb(regs, MUSB_BUSCTL_OFFSET(ep->epnum, + MUSB_TXFUNCADDR), 127); csr = musb_readw(epio, MUSB_TXCSR); - if (WARN(retries-- < 1, - "Could not flush host TX%d fifo: csr: %04x\n", - ep->epnum, csr)) - return; - mdelay(1); + retries--; + if (retries == 0) { + /* can happen if the USB clocks are OFF */ + DBG(3, "Could not flush host TX%d " + "fifo: csr=0x%04x\n", ep->epnum, csr); + break; + } + udelay(1); } + /* clear any errors */ + csr &= ~(MUSB_TXCSR_H_ERROR + | MUSB_TXCSR_H_RXSTALL + | MUSB_TXCSR_H_NAKTIMEOUT); + musb_writew(epio, MUSB_TXCSR, csr); + + /* restore endpoint address */ + musb_writeb(regs, MUSB_BUSCTL_OFFSET(ep->epnum, MUSB_TXFUNCADDR), addr); } static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep) @@ -1128,7 +1145,9 @@ void musb_host_tx(struct musb *musb, u8 epnum) dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum); status = -ETIMEDOUT; - + } else if (tx_csr & MUSB_TXCSR_TXPKTRDY) { + /* BUSY - can happen during USB transfer cancel */ + return; } else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) { dev_dbg(musb->controller, "TX end=%d device not responding\n", epnum); |