On 05/20/2016 08:06 PM, Andrew Goodbody wrote:
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@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/usb/musb/musb_host.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/musb/musb_host.c
b/drivers/usb/musb/musb_host.c index 30e0d65..777ff30 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -999,6 +999,8 @@ static void musb_bulk_nak_timeout(struct musb
*musb, struct musb_hw_ep *ep,
/* clear nak timeout bit */
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);
Can we not clear both in one write?
Section 16.3.8.2.2.1.2 of the TRM says to clear REQPKT before DATAERR_NAKTIMEOUT.
Right, the MUSB programmer's guide also says that. Then a comment wouldn't
hurt here.
Andrew
MBR, Sergei
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