From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754572AbcEWN0o (ORCPT ); Mon, 23 May 2016 09:26:44 -0400 Received: from mail1.bemta3.messagelabs.com ([195.245.230.173]:47295 "EHLO mail1.bemta3.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754436AbcEWN0l convert rfc822-to-8bit (ORCPT ); Mon, 23 May 2016 09:26:41 -0400 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrMKsWRWlGSWpSXmKPExsVyU6Zroi4Dq3O 4waajwhb/7yxitWhevJ7N4vKuOWwWi5a1MlucWXWL3WLBxkeMDmweD6b+Z/LYP3cNu8fxG9uZ PD5vkgtgiWLNzEvKr0hgzbj3LKpghVDF8zXtrA2MPfxdjFwcQgKbGCW+zpnCCOHsZZRob94L5 HBysAmYSex6tY4dxBYRiJA4seAiM0gRs8BrRon7F6YzgSSEBQIltl1fAlUUJLH0eCeUbSWx6t 9sZhCbRUBV4tHvJ2BDeQVcJZac7mGC2HaWUeLUpXesIAlOATeJ5rffwRoYBWQlvjSuBrOZBcQ lbj2ZD7ZMQkBAYsme88wQtqjEy8f/WCFsA4mtS/exQNgKEj96T0HVWEv8e3CXCWKOjsSC3Z/Y IGxtiWULXzNDHCQocXLmE5YJjGKzkKybhaRlFpKWWUhaFjCyrGLUKE4tKkst0jU00UsqykzPK MlNzMzRNTQw1stNLS5OTE/NSUwq1kvOz93ECIxMBiDYwbhiu+chRkkOJiVR3pM7nMKF+JLyUy ozEosz4otKc1KLDzHKcHAoSfD+ZXYOFxIsSk1PrUjLzAGmCJi0BAePkgivIQtQmre4IDG3ODM dInWKUVFKnJcHJCEAksgozYNrg6WlS4yyUsK8jECHCPEUpBblZpagyr9iFOdgVBLmNQKZwpOZ VwI3/RXQYiagxQ+lHUAWlyQipKQaGBu2L1Q0Ln+yP3bv3aLtkb+E5gfPMqiNj3kk/f7aGzWv7 /XLLlRbyjSytPM5Ofz3OhesxbVJdzefUuXagy28bJHungWV62U7s/tmv+1tPdwy6avEw417RO UW3uh++2bNj4VHXhmstN0wS2FSsdhLRgHlC09DbOWvnCnoF3sda5yhzLWZtXzzIiWW4oxEQy3 mouJEABg7PU5GAwAA X-Env-Sender: andrew.goodbody@cambrionix.com X-Msg-Ref: server-9.tower-140.messagelabs.com!1464009984!33122336!1 X-Originating-IP: [217.28.138.145] 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 V2 2/2] usb: musb: Stop bulk endpoint while queue is rotated Thread-Topic: [PATCH V2 2/2] usb: musb: Stop bulk endpoint while queue is rotated Thread-Index: AQHRtOrNDeZOdsfoq0qoHTZEXPmD3Z/GZYgAgAAaspA= Date: Mon, 23 May 2016 13:26:22 +0000 Message-ID: <6b25b4a5cc104ea0adc5bd006040529b@SEHSTE15D2BE2.hs20.net> References: <1464004844-26553-1-git-send-email-andrew.goodbody@cambrionix.com> <1464004844-26553-3-git-send-email-andrew.goodbody@cambrionix.com> In-Reply-To: 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] > > Hello. > > On 5/23/2016 3:00 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 > > --- > > V2 added comment about clearing REQPKT before DATAERR_NAKTIMEOUT > > > > drivers/usb/musb/musb_host.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/usb/musb/musb_host.c > > b/drivers/usb/musb/musb_host.c index 2966596..676cb98 100644 > > --- a/drivers/usb/musb/musb_host.c > > +++ b/drivers/usb/musb/musb_host.c > > @@ -997,6 +997,12 @@ 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; > > + /* > > + * Need to stop the transaction by clearing REQPKT before > > Transcation? Maybe transfer? The quote from the TRM is "If the DATAERR_NAKTIMEOUT bit is set, the controller can be directed either to continue trying this transaction (until it times out again) by clearing the DATAERR_NAKTIMEOUT bit or to abort the transaction by clearing REQPKT bit before clearing the DATAERR_NAKTIMEOUT bit." So 'transaction' is correct. > > + * DATAERR_NAKTIMEOUT ref TRM section 16.3.8.2.2.1.2 > > Which TRM? Do you understand that the MUSB core is used by multiple > SoCs? > I'd recommend referring just to the "abstract" manual or the MUSB > programmer's guide (section 9.2.2 if you want an exact ref.). That would be the AM335x Sitara Processors TRM. I don't have the MUSB programmer's guide, is it available online somewhere? I do not understand what you mean by the "abstract" manual. Would you be OK with "ref MUSB Programmer's Guide section 9.2.2" Andrew > [...] > > MBR, Sergei