| From 7b2c17f829545df27a910e8d82e133c21c9a8c9c Mon Sep 17 00:00:00 2001 |
| From: Andrew Goodbody <andrew.goodbody@cambrionix.com> |
| Date: Tue, 31 May 2016 10:05:27 -0500 |
| Subject: usb: musb: Stop bulk endpoint while queue is rotated |
| |
| From: Andrew Goodbody <andrew.goodbody@cambrionix.com> |
| |
| 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> |
| |
| --- |
| 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 |
| @@ -995,9 +995,15 @@ 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); |
| |
