From: Andrew Goodbody <andrew.goodb...@cambrionix.com>
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
Signed-off-by: Bin Liu <b-...@ti.com>
---
drivers/usb/musb/musb_host.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 327f39c..d227a71 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -992,9 +992,15 @@ 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);
--
1.9.1
--
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
