From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ross Zwisler Subject: Re: [PATCH] drm/radeon: Fix regression with suspend/resume Date: Tue, 17 Feb 2015 10:49:06 -0700 Message-ID: <1424195346.12687.6.camel@theros.lm.intel.com> References: <1423773026-5941-1-git-send-email-ross.zwisler@linux.intel.com> <54DD6469.9060809@daenzer.net> <1423886115.5037.12.camel@theros.lm.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: "Deucher, Alexander" Cc: Michel =?ISO-8859-1?Q?D=E4nzer?= , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , Dave Airlie , Lauri Kasanen , "Koenig, Christian" List-Id: dri-devel@lists.freedesktop.org On Sat, 2015-02-14 at 06:25 +0000, Deucher, Alexander wrote: > > -----Original Message----- > > From: Ross Zwisler [mailto:ross.zwisler@linux.intel.com] > > Sent: Friday, February 13, 2015 10:55 PM > > To: Michel D=C3=A4nzer > > Cc: linux-kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; = Deucher, > > Alexander; Dave Airlie; Lauri Kasanen; Koenig, Christian > > Subject: Re: [PATCH] drm/radeon: Fix regression with suspend/resume > >=20 > > On Fri, 2015-02-13 at 11:41 +0900, Michel D=C3=A4nzer wrote: > > > On 13.02.2015 05:30, Ross Zwisler wrote: > > > > This patch reverts the changes made in this commit: > > > > > > > > deadcb36f49b ("drm/radeon: Use two-ended allocation by size, = v2") > > > > > > > > That patch caused a regression on my system where the bottom of= the > > > > screen flickers after my laptop goes thorough a suspend and res= ume. > > > > > > What kind of flicker is it? E.g. does it only affect X or also co= nsole, > > > does it flicker all the time or only when there is activity, what= does > > > it look like, ... > >=20 > > It's kind of hard to describe it precisely, so I made a video. :) > >=20 > > http://youtu.be/ESm9SMnr0do > >=20 > > It only affects X, not the console, and it seems to go away if you = log > > out back to the login manager (I'm using GDM on Fedora 20) and back= into > > your window manager. >=20 > Does a VT switch or forcing a dpms cycle (sleep 5; xset dpms force of= f) > also fix it? It doesn't look related to the patch in question at all= =2E=20 > Is the flickering 100% reproducible or does it only happen > periodically? =46rom kernels 3.14 or so (when the deadcb36f49b patch was introduced) till 3.18 it happened 100% of the time. With 3.19 it only seems to happen maybe 50% of the time, but is still very easily reproducible. It's entirely possible that the patch isn't the root cause, but it just brought out a bug somewhere else. All I know is that I did a bisect, and with the commit before this the issue never happens, and after this commit it happens 100% of the time. :) Also, reverting that commit wit= h 3.19 makes the issue go away. Nope, "xset dpms force off" doesn't fix it. After the screen goes black and comes back, the flicker is still there. - Ross