From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933500AbcGGBcw (ORCPT ); Wed, 6 Jul 2016 21:32:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50021 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933040AbcGGBTa (ORCPT ); Wed, 6 Jul 2016 21:19:30 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrew Goodbody , Bin Liu Subject: [PATCH 4.6 21/31] usb: musb: Stop bulk endpoint while queue is rotated Date: Wed, 6 Jul 2016 18:19:11 -0700 Message-Id: <20160707011558.368035452@linuxfoundation.org> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160707011557.518104444@linuxfoundation.org> References: <20160707011557.518104444@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Goodbody 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 Signed-off-by: Bin Liu Signed-off-by: Greg Kroah-Hartman --- 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);