This is a note to let you know that I've just added the patch titled
usb: musb: Stop bulk endpoint while queue is rotated
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-musb-stop-bulk-endpoint-while-queue-is-rotated.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7b2c17f829545df27a910e8d82e133c21c9a8c9c Mon Sep 17 00:00:00 2001
From: Andrew Goodbody <andrew.goodbody@xxxxxxxxxxxxxx>
Date: Tue, 31 May 2016 10:05:27 -0500
Subject: usb: musb: Stop bulk endpoint while queue is rotated
From: Andrew Goodbody <andrew.goodbody@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/musb/musb_host.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -950,9 +950,15 @@ static void musb_bulk_nak_timeout(struct
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);
Patches currently in stable-queue which might be from andrew.goodbody@xxxxxxxxxxxxxx are
queue-3.14/usb-musb-stop-bulk-endpoint-while-queue-is-rotated.patch
queue-3.14/usb-musb-ensure-rx-reinit-occurs-for-shared_fifo-endpoints.patch
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