From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757816AbaHGOgk (ORCPT ); Thu, 7 Aug 2014 10:36:40 -0400 Received: from mail-wi0-f177.google.com ([209.85.212.177]:64821 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757335AbaHGOgi (ORCPT ); Thu, 7 Aug 2014 10:36:38 -0400 Date: Thu, 7 Aug 2014 16:36:49 +0200 From: Daniel Vetter To: Jiri Kosina Cc: Pavel Machek , Linux-pm mailing list , intel-gfx , "Rafael J. Wysocki" , kernel list Subject: Re: [Intel-gfx] 3.15-rc: regression in suspend Message-ID: <20140807143649.GD8727@phenom.ffwll.local> Mail-Followup-To: Jiri Kosina , Pavel Machek , Linux-pm mailing list , intel-gfx , "Rafael J. Wysocki" , kernel list References: <20140607120614.GB5309@amd.pavel.ucw.cz> <20140607231124.GA3611@amd.pavel.ucw.cz> <20140609102328.GA25332@amd.pavel.ucw.cz> <20140625223522.GA5923@xo-6d-61-c0.localdomain> <20140707083908.GE5821@phenom.ffwll.local> <20140711192629.GA20015@amd.pavel.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 3.15.0-rc3+ User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 07, 2014 at 02:47:21PM +0200, Jiri Kosina wrote: > On Fri, 11 Jul 2014, Pavel Machek wrote: > > > > > > Ok, so I have set up machines for ktest / autobisect, and found out that > > > > > 3.16-rc1 no longer has that problem. Oh well, bisect would not be fun, > > > > > anyway... > > > > > > > > I am still seeing the problem with 3.16-rc2. > > > > > > I'm confused now. Is the bisect result > > > > > > commit 773875bfb6737982903c42d1ee88cf60af80089c > > > Author: Daniel Vetter > > > Date: Mon Jan 27 10:00:30 2014 +0100 > > > > > > drm/i915: Don't set the 8to6 dither flag when not scaling > > > > > > now the culprit or not? Or do we have 2 different bugs at hand here? > > > > Three different issues, it seems. Two ring initialization problems, > > one went away in 3.16 (for me), second did not (suspend for jikos), > > third -- trivial issue with 8to6 dither. > > The patch below seems to finally cure the problem at my system; I've just > attached it to freedesktop bugzilla, but sending it to this thread as well > to hopefully get as much testing coverage by affected people as possible. > > I am going on with testing whether it really completely fixes the problem > or just made it less likely. Picked up for -fixes, thanks for the patch. -Daniel > > > > > > From: Jiri Kosina > Subject: [PATCH] drm/i915: read HEAD register back in init_ring_common() to enforce ordering > > Withtout this, ring initialization fails reliabily during resume with > > [drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f001 head ffffff8804 tail 00000000 start 000e4000 > > Signed-off-by: Jiri Kosina > --- > drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c > index 279488a..7add7ee 100644 > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c > @@ -517,6 +517,9 @@ static int init_ring_common(struct intel_engine_cs *ring) > else > ring_setup_phys_status_page(ring); > > + /* Enforce ordering by reading HEAD register back */ > + I915_READ_HEAD(ring); > + > /* Initialize the ring. This must happen _after_ we've cleared the ring > * registers with the above sequence (the readback of the HEAD registers > * also enforces ordering), otherwise the hw might lose the new ring > > -- > Jiri Kosina > SUSE Labs > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch