From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH 2/2] pinctrl: baytrail: Serialize all register access Date: Fri, 30 Oct 2015 08:26:59 -0700 Message-ID: <20151030152659.GA29070@kroah.com> References: <1438689794-14355-1-git-send-email-mika.westerberg@linux.intel.com> <1438689794-14355-2-git-send-email-mika.westerberg@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39373 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752247AbbJ3P1D (ORCPT ); Fri, 30 Oct 2015 11:27:03 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Lucas De Marchi Cc: Mika Westerberg , Linus Walleij , Mathias Nyman , Heikki Krogerus , "linux-gpio@vger.kernel.org" , lkml On Fri, Oct 30, 2015 at 12:48:38PM -0200, Lucas De Marchi wrote: > Hi Mika and Linus, > > CC'ing Greg. > > On Tue, Aug 4, 2015 at 9:03 AM, Mika Westerberg > wrote: > > There is a hardware issue in Intel Baytrail where concurrent GPIO register > > access might result reads of 0xffffffff and writes might get dropped > > completely. > > > > Prevent this from happening by taking the serializing lock in all places > > where it is possible that more than one thread might be accessing the > > hardware concurrently. > > > > Signed-off-by: Mika Westerberg > > --- > > Now that this is on 4.2, can we get it on stable branches? I was > hitting this bug for some time on MinnowBoard Max and this week I had > some time to take a look on how to fix it. Good timing, it had already > been fixed. Applying this patch the issue is gone on top of 4.1.12. > > I'm using these patches from Linus Torvalds' tree: > 39ce815 pinctrl: baytrail: Serialize all register access > 78e1c89 pinctrl: baytrail: Use raw_spinlock for locking > > > The ones to Cherryview could be sent too but I couldn't test them. > > Leaving the patch below for reference. This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly.