Commit 7b2c17f8 authored May 31, 2016 by Andrew Goodbody Committed by Greg Kroah-Hartman Jun 01, 2016

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>

parent f3eec0cf

drivers/usb/musb/musb_host.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -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);