From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756000AbcETRYk (ORCPT ); Fri, 20 May 2016 13:24:40 -0400 Received: from mail1.bemta3.messagelabs.com ([195.245.230.165]:35138 "EHLO mail1.bemta3.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752319AbcETRYi convert rfc822-to-8bit (ORCPT ); Fri, 20 May 2016 13:24:38 -0400 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrCKsWRWlGSWpSXmKPExsVyU6aHU9fLwz7 cYN8nS4v/dxaxWjQvXs9mcXnXHDaLRctamS3OrLrFbrFg4yNGBzaPB1P/M3nsn7uG3eP4je1M Hp83yQWwRLFm5iXlVySwZtz8+5Cl4BVvxcvdpxgbGHdzdzFycQgJbGGUeN/Szgrh7GWUWLz0C FsXIycHm4CZxK5X69hBbBGBCIkTCy4ygxQxC7xmlLh/YToTSEJYwFdi1/ozUEV+Es1LbzJD2G 4SvxdNYwGxWQRUJX7s+gZWzyvgKnF/yjIWiG2HmSS+TfvCCpLgBGrYcukYmM0oICvxpXE12CB mAXGJW0/mgzVLCAhILNlznhnCFpV4+fgfK4RtILF16T4WCFtB4kfvKagaa4l/D+4yQczRkViw +xMbhK0tsWzha2aIgwQlTs58wjKBUWwWknWzkLTMQtIyC0nLAkaWVYwaxalFZalFuoaGeklFm ekZJbmJmTm6hgbGermpxcWJ6ak5iUnFesn5uZsYgbHJAAQ7GFf/djrEKMnBpCTKqyZuHy7El5 SfUpmRWJwRX1Sak1p8iFGGg0NJgveeG1BOsCg1PbUiLTMHmCRg0hIcPEoivP9A0rzFBYm5xZn pEKlTjIpS4ryi7kAJAZBERmkeXBssMV1ilJUS5mUEOkSIpyC1KDezBFX+FaM4B6OSMO8NkPE8 mXklcNNfAS1mAlp8S8wGZHFJIkJKqoHRcsJvhdAaV5kHH8V+tXld+u2ic5VZlGUiJ1MXW+eh0 DfR9x+WCK/LkN3/6VTongsm9S3+v7wyev0rwo97PVvD5eHAfSz8xo0JJc57Ki2qw3SYF2hz/6 z9vFP97IQ5/rO95vu0sUypnKcYe+WF8mTr4sQPpYky2+VmPQ08pXMvda3wsztrnvYosRRnJBp qMRcVJwIAasnq00cDAAA= X-Env-Sender: andrew.goodbody@cambrionix.com X-Msg-Ref: server-4.tower-140.messagelabs.com!1463765066!32903154!2 X-Originating-IP: [217.28.140.9] X-StarScan-Received: X-StarScan-Version: 8.34; banners=-,-,- X-VirusChecked: Checked From: Andrew Goodbody To: Sergei Shtylyov , "b-liu@ti.com" CC: "gregkh@linuxfoundation.org" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: RE: [PATCH 2/2] usb: musb: Stop bulk endpoint while queue is rotated Thread-Topic: [PATCH 2/2] usb: musb: Stop bulk endpoint while queue is rotated Thread-Index: AQHRsqdFFRyY/KzTlE+UQpildgn8+5/B8S0AgAAcrqD///IdgIAAE23A Date: Fri, 20 May 2016 17:24:25 +0000 Message-ID: References: <1463755902-12922-1-git-send-email-andrew.goodbody@cambrionix.com> <1463755902-12922-3-git-send-email-andrew.goodbody@cambrionix.com> <7a4fb42ac94140d7a5d34eb1c0b5934b@THHSTE15D2BE2.hs20.net> <5aab1e5e-fd86-2145-d965-07e82d73cd62@cogentembedded.com> In-Reply-To: <5aab1e5e-fd86-2145-d965-07e82d73cd62@cogentembedded.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [46.17.166.30] x-exclaimer-md-config: 266e7a57-cddd-49fd-bdea-19bca6d40303 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Sergei Shtylyov [mailto:sergei.shtylyov@cogentembedded.com] > On 05/20/2016 08:06 PM, Andrew Goodbody wrote: > > >>> 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 > > >>> Cc: stable@vger.kernel.org > >>> --- > >>> drivers/usb/musb/musb_host.c | 2 ++ > >>> 1 file changed, 2 insertions(+) > >>> > >>> diff --git a/drivers/usb/musb/musb_host.c > >>> b/drivers/usb/musb/musb_host.c index 30e0d65..777ff30 100644 > >>> --- a/drivers/usb/musb/musb_host.c > >>> +++ b/drivers/usb/musb/musb_host.c > >>> @@ -999,6 +999,8 @@ static void musb_bulk_nak_timeout(struct musb > >> *musb, struct musb_hw_ep *ep, > >>> /* clear nak timeout bit */ > >>> 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); > >> > >> Can we not clear both in one write? > > > > Section 16.3.8.2.2.1.2 of the TRM says to clear REQPKT before > DATAERR_NAKTIMEOUT. > > Right, the MUSB programmer's guide also says that. Then a comment > wouldn't hurt here. I'll add that for v2, thanks. Andrew > > Andrew > > MBR, Sergei