From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 3/6] drm/i915: Don't emit semaphore wait if wrap happened Date: Thu, 06 Dec 2012 12:24:04 +0000 Message-ID: References: <1354626725-8521-1-git-send-email-mika.kuoppala@intel.com> <1354626725-8521-4-git-send-email-mika.kuoppala@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id F3368E64E0 for ; Thu, 6 Dec 2012 04:24:16 -0800 (PST) In-Reply-To: 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: Daniel Vetter , Paulo Zanoni Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Thu, 6 Dec 2012 13:14:09 +0100, Daniel Vetter wrote: > On Thu, Dec 6, 2012 at 12:41 PM, Paulo Zanoni wrote: > > 2012/12/6 Daniel Vetter : > >> On Wed, Dec 5, 2012 at 9:44 PM, Paulo Zanoni wrote: > >>> 2012/12/4 Mika Kuoppala : > >>>> If wrap just happened we need to prevent emitting waits for > >>>> pre wrap values. Detect this and emit no-ops instead. > >>>> > >>>> v2: Use olr > seqno to detect wrap instead of *seqno == 0 > >>>> as suggested by Chris Wilson. > >>> > >>> This commit introduces a bug on Haswell. Now when I'm typing my > >>> password on GDM the screen keeps doing wrong rendering. It "blinks > >>> blue". After logging in I don't see more prodrm/i915: Set initial seqno value close to wrap boundaryblems. > >> > >> Just now I've taken out "drm/i915: Set initial seqno value close to > >> wrap boundary" since QA complained that it regresses things. Does that > >> help for you, too? > > > > It helps: besides the "wrong rendering at GDM screen" I was also > > getting GPU hangs (when starting X, when running dmesg, when alt+tab, > > etc), and it seems with today's dinq I don't get the gpu hangs > > anymore. I still get the "wrong rendering" problem and it goes away if > > we revert the "Don't emit semaphore wait if wrap happened". > > Ok, looks like we have still some fish left to fry here. I've backed > out the 2nd patch, too. And I guess we need some more tests in i-g-t > to check semaphore correctness, we seem to have some serious gaps ... I wouldn't back that out too quickly as it seems that Paulo has some debugging to do first. A few WARNs would be a good start... -Chris -- Chris Wilson, Intel Open Source Technology Centre