From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 5/7] drm/i915: Error checks in gen6_set_rps Date: Sun, 09 Sep 2012 19:25:40 +0100 Message-ID: <275ffc$6hj53c@fmsmga002.fm.intel.com> References: <1347072225-10654-1-git-send-email-ben@bwidawsk.net> <1347072225-10654-6-git-send-email-ben@bwidawsk.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id 4A1209ECE0 for ; Sun, 9 Sep 2012 11:25:50 -0700 (PDT) In-Reply-To: <1347072225-10654-6-git-send-email-ben@bwidawsk.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org Cc: Ben Widawsky List-Id: intel-gfx@lists.freedesktop.org On Fri, 7 Sep 2012 19:43:42 -0700, Ben Widawsky wrote: > With the new "standardized" sysfs interfaces we need to be a bit more > careful about setting the RPS values. > > Because the sysfs code and the rps workqueue can run at the same time, > if the sysfs setter wins the race to the mutex, the workqueue can come > in and set a value which is out of range (ie. we're no longer protecting > by RPINTLIM). > > I was not able to actually make this error occur in testing. > > Signed-off-by: Ben Widawsky Good catch, care to squeeze the comment into a single line ;-) Reviewed-by: Chris Wilson -Chris -- Chris Wilson, Intel Open Source Technology Centre