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author | Linus Walleij <linus.walleij@linaro.org> | 2015-12-21 09:36:21 +0100 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2015-12-21 09:36:21 +0100 |
commit | 0529357f102b96f68bc199f858d1c3b07f4b674c (patch) | |
tree | eaa047952a768099e00a5245afa0d84799df6990 /drivers/usb/musb/musb_host.c | |
parent | a9f1a3e4c1c7dc82711bc22dc52c7b0d6912ed56 (diff) | |
parent | 4ef7675344d687a0ef5b0d7c0cee12da005870c0 (diff) | |
download | op-kernel-dev-0529357f102b96f68bc199f858d1c3b07f4b674c.zip op-kernel-dev-0529357f102b96f68bc199f858d1c3b07f4b674c.tar.gz |
Merge tag 'v4.4-rc6' into devel
Linux 4.4-rc6
Diffstat (limited to 'drivers/usb/musb/musb_host.c')
-rw-r--r-- | drivers/usb/musb/musb_host.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 26c65e6..795a45b 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -112,22 +112,32 @@ static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep) struct musb *musb = ep->musb; void __iomem *epio = ep->regs; u16 csr; - u16 lastcsr = 0; int retries = 1000; 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_TXCSR_TXPKTRDY; musb_writew(epio, MUSB_TXCSR, csr); csr = musb_readw(epio, MUSB_TXCSR); - if (WARN(retries-- < 1, + + /* + * FIXME: sometimes the tx fifo flush failed, it has been + * observed during device disconnect on AM335x. + * + * To reproduce the issue, ensure tx urb(s) are queued when + * unplug the usb device which is connected to AM335x usb + * host port. + * + * I found using a usb-ethernet device and running iperf + * (client on AM335x) has very high chance to trigger it. + * + * Better to turn on dev_dbg() in musb_cleanup_urb() with + * CPPI enabled to see the issue when aborting the tx channel. + */ + if (dev_WARN_ONCE(musb->controller, retries-- < 1, "Could not flush host TX%d fifo: csr: %04x\n", ep->epnum, csr)) return; - mdelay(1); } } |