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authorAndrew Goodbody <andrew.goodbody@cambrionix.com>2016-05-31 18:05:27 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-06-02 00:58:59 +0300
commit7b2c17f829545df27a910e8d82e133c21c9a8c9c (patch)
treee26c5d4a6a23325f3a8a080217d2060bd7c38509 /drivers/usb/musb/musb_host.c
parentf3eec0cf784e0d6c47822ca6b66df3d5812af7e6 (diff)
downloadlinux-7b2c17f829545df27a910e8d82e133c21c9a8c9c.tar.xz
usb: musb: Stop bulk endpoint while queue is rotated
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> Cc: stable@vger.kernel.org Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/musb/musb_host.c')
-rw-r--r--drivers/usb/musb/musb_host.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 327f39c8c174..d227a71d85e1 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);