From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750957AbcEHLUy (ORCPT ); Sun, 8 May 2016 07:20:54 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:36432 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750791AbcEHLUx (ORCPT ); Sun, 8 May 2016 07:20:53 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Sun, 8 May 2016 13:20:38 +0200 From: Stefan Richter To: "Zanoni, Paulo R" Cc: "airlied@redhat.com" , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "Vetter, Daniel" Subject: Re: Regression of v4.6-rc vs. v4.5 bisected: a98ee79317b4 "drm/i915/fbc: enable FBC by default on HSW and BDW" Message-ID: <20160508132038.0deaad7c@kant> In-Reply-To: <20160508121818.5f1541fe@kant> References: <20160426210008.2f79fcdf@kant> <20160429100741.6be95385@kant> <20160430155154.597829ca@kant> <20160505194506.63b9c113@kant> <1462474211.29701.21.camel@intel.com> <20160508121818.5f1541fe@kant> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.29; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On May 08 Stefan Richter wrote: > On May 05 Zanoni, Paulo R wrote: > > If you don't want to keep carrying a manual revert, you can just boot > > with i915.enable_fbc=0 for now (or write a /etc/modprobe.d file). Also, > > it would be good to know in case you still somehow see the machine > > hangs even with FBC disabled. > > As expected, i915.enable_fbc=0 works fine. > No freeze within 2.5 days uptime; tested on v4.6-rc6. Furthermore, I checked out drm-intel.git (v4.6-rc6-962-g91567024d358 "drm-intel-nightly: 2016y-05m-06d-14h-29m-58s UTC integration manifest") and applied "git diff v4.6-rc6..." on top of v4.6-rc6. I booted the result once with default i915.enable_fbc, i.e. FBC enabled, performed the test which Daniel asked for (I will post the results in another message), then started X11. - The good news: I was able to switch back and forth between the sddm greeter screen on tty7, the text consoles at tty1...6, and the logger at tty12 --- without getting any FIFO underrun messages and without getting stuck with a blank screen. - The bad news: Less than a minute after login into sddm, just after having started openbox + lxpanel + konsole, the kernel froze again without netconsole output. I am now on 4.6.0-rc6+intel-drm-nightly with i915.enable_fbc=0. This is running fine so far. (uptime is just 30 minutes now though, so that doesn't say a lot.) Again, switching between ttys works without FIFO underruns, unlike plain v4.6-rc6. Not sure if it is coincidence or if this is because somebody fixed something. Like v4.6-rc6 and older,4.6.0-rc6+intel-drm-nightly still exhibits the following behaviour: If I switch the displayport connected monitor off and on again, the following messages are logged when the monitor comes on: [drm:intel_set_cpu_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A [drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun Other than these messages, there is nothing extraordinary going on. -- Stefan Richter -======----- -=-= -=--- http://arcgraph.de/sr/