Commit 7ba4a8aa authored by Andrew Goodbody's avatar Andrew Goodbody Committed by Ben Hutchings

usb: musb: Stop bulk endpoint while queue is rotated

commit 7b2c17f8 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: default avatarAndrew Goodbody <andrew.goodbody@cambrionix.com>
Signed-off-by: default avatarBin Liu <b-liu@ti.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 442f839f
...@@ -1384,9 +1384,15 @@ static void musb_bulk_rx_nak_timeout(struct musb *musb, struct musb_hw_ep *ep) ...@@ -1384,9 +1384,15 @@ static void musb_bulk_rx_nak_timeout(struct musb *musb, struct musb_hw_ep *ep)
musb_ep_select(mbase, ep->epnum); musb_ep_select(mbase, ep->epnum);
dma = is_dma_capable() ? ep->rx_channel : NULL; 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_readw(epio, MUSB_RXCSR);
rx_csr |= MUSB_RXCSR_H_WZC_BITS; 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; rx_csr &= ~MUSB_RXCSR_DATAERROR;
musb_writew(epio, MUSB_RXCSR, rx_csr); musb_writew(epio, MUSB_RXCSR, rx_csr);
......
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