From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751459AbdA3CKz (ORCPT ); Sun, 29 Jan 2017 21:10:55 -0500 Received: from shells.gnugeneration.com ([66.240.222.126]:42090 "HELO shells.gnugeneration.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751018AbdA3CKr (ORCPT ); Sun, 29 Jan 2017 21:10:47 -0500 Date: Sun, 29 Jan 2017 20:04:05 -0600 From: lkml@pengaru.com To: linux-kernel@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk Subject: Re: BUG: 4.10 i915 drm display noise regression - bisected to a6a7cc4b7 Message-ID: <20170130020405.GS3712@shells.gnugeneration.com> References: <20170109063240.GB9125@shells.gnugeneration.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170109063240.GB9125@shells.gnugeneration.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 09, 2017 at 12:32:40AM -0600, lkml@pengaru.com wrote: > Hello all, > > I'm experiencing display noise in the form of 8x1 pixel bars spuriously > appearing in random locations. This doesn't happen on 4.9, the machine > is an X61s, a Core2Duo 1.8Ghz w/XGA via LVDS. > > I was able to bisect the issue to a6a7cc4b7: > > commit a6a7cc4b7db6deaeca11cdd38844ea147a354c7a > Author: Chris Wilson > Date: Fri Nov 18 21:17:46 2016 +0000 > > drm/i915: Always flush the dirty CPU cache when pinning the scanout > > Currently we only clflush the scanout if it is in the CPU domain. Also > flush if we have a pending CPU clflush. We also want to treat the > dirtyfb path similar, and flush any pending writes there as well. > > v2: Only send the fb flush message if flushing the dirt on flip > v3: Make flush-for-flip and dirtyfb look more alike since they serve > similar roles as end-of-frame marker. > > Reproduction is simple, just run this native drm eye candy program: > https://github.com/vcaputo/rototiller > This regression still remains as of 4.10.0-rc6. Chris Wilson had posted a fix: https://www.spinics.net/lists/kernel/msg2420777.html But it seems to have been ignored so far. How do we get this fixed in 4.10 before it ships? Regards, Vito Caputo