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| author | Andrew Goodbody <andrew.goodbody@cambrionix.com> | 2016-05-31 10:05:27 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-07-11 09:30:01 -0700 |
| commit | b79d89e3ea2732c475531c348210a56d64fef50d (patch) | |
| tree | 5a287959c1fbf52326171f54546daa71ac67a59b | |
| parent | 7adf3cd844622756befc599ef729b87590259876 (diff) | |
| download | lwn-b79d89e3ea2732c475531c348210a56d64fef50d.tar.gz lwn-b79d89e3ea2732c475531c348210a56d64fef50d.zip | |
usb: musb: Stop bulk endpoint while queue is rotated
commit 7b2c17f829545df27a910e8d82e133c21c9a8c9c upstream.
Ensure that the endpoint is stopped by clearing REQPKT before
clearing DATAERR_NAKTIMEOUT before rotating the queue on the
dedicated bulk endpoint.
This addresses an issue where a race could result in the endpoint
receiving data before it was reprogrammed resulting in a warning
about such data from musb_rx_reinit before it was thrown away.
The data thrown away was a valid packet that had been correctly
ACKed which meant the host and device got out of sync.
Signed-off-by: Andrew Goodbody <andrew.goodbody@cambrionix.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/musb/musb_host.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 2f8ad7f1f482..d2dee56261ae 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -995,9 +995,15 @@ static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep, if (is_in) { dma = is_dma_capable() ? ep->rx_channel : NULL; - /* clear nak timeout bit */ + /* + * Need to stop the transaction by clearing REQPKT first + * then the NAK Timeout bit ref MUSBMHDRC USB 2.0 HIGH-SPEED + * DUAL-ROLE CONTROLLER Programmer's Guide, section 9.2.2 + */ rx_csr = musb_readw(epio, MUSB_RXCSR); rx_csr |= MUSB_RXCSR_H_WZC_BITS; + rx_csr &= ~MUSB_RXCSR_H_REQPKT; + musb_writew(epio, MUSB_RXCSR, rx_csr); rx_csr &= ~MUSB_RXCSR_DATAERROR; musb_writew(epio, MUSB_RXCSR, rx_csr); |