Messages in this thread | | | Subject | Re: [PATCH 2/2] usb: musb: Stop bulk endpoint while queue is rotated | From | Sergei Shtylyov <> | Date | Fri, 20 May 2016 19:21:12 +0300 |
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On 05/20/2016 05:51 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@cambrionix.com> > Cc: stable@vger.kernel.org > --- > 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?
[...]
MBR, Sergei
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