> From: Sergei Shtylyov [mailto:sergei.shtyl...@cogentembedded.com] > 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.goodb...@cambrionix.com> > > Cc: sta...@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?
Section 16.3.8.2.2.1.2 of the TRM says to clear REQPKT before DATAERR_NAKTIMEOUT. Andrew > [...] > > MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
