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usb: musb: Stop bulk endpoint while queue is rotated

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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>
This commit is contained in:
Andrew Goodbody 2016-05-31 10:05:27 -05:00 committed by Greg Kroah-Hartman
parent 089a2d8400
commit a2cf3427dc
1 changed files with 7 additions and 1 deletions
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8
drivers/usb/musb/musb_host.c
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@ -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);