Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752133AbcDRTrH (ORCPT ); Mon, 18 Apr 2016 15:47:07 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:40897 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751660AbcDRTrE (ORCPT ); Mon, 18 Apr 2016 15:47:04 -0400 Subject: Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid To: Jani Nikula , sonika.jindal@intel.com References: <56CE22DB.6050108@canonical.com> <87lh63uago.fsf@intel.com> <56D76208.7020702@canonical.com> <56F97A65.3010608@canonical.com> Cc: shashank.sharma@intel.com, rodrigo.vivi@intel.com, Daniel Vetter , David Airlie , intel-gfx , dri-devel , LKML , LaMont Jones From: Joseph Salisbury Message-ID: <571539B3.6060307@canonical.com> Date: Mon, 18 Apr 2016 15:46:59 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <56F97A65.3010608@canonical.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3201 Lines: 100 On 03/28/2016 02:39 PM, Joseph Salisbury wrote: > On 03/02/2016 04:58 PM, Joseph Salisbury wrote: >> On 02/29/2016 04:33 AM, Jani Nikula wrote: >>> On Wed, 24 Feb 2016, Joseph Salisbury wrote: >>>> Hi Sonika, >>>> >>>> A kernel bug report was opened against Ubuntu [0]. After a kernel >>>> bisect, it was found that reverting the following commit resolved this bug: >>>> >>>> commit 237ed86c693d8a8e4db476976aeb30df4deac74b >>>> Author: Sonika Jindal >>>> Date: Tue Sep 15 09:44:20 2015 +0530 >>>> >>>> drm/i915: Check live status before reading edid >>>> >>>> >>>> >>>> The regression was introduced as of v4.4-rc1. >>>> >>>> I was hoping to get your feedback, since you are the patch author. Do >>>> think increasing the number of tries in intel_hdmi_detect() is worth >>>> trying? Do you think gathering any additional data will help diagnose >>>> this issue, or would it be best to submit a revert request? >> Thanks for the info. I will have all of these commits tested. >> >> >>> There are at least the following commits claiming to fix issues in the >>> above commit. Please make sure you have them. >>> >>> BR, >>> Jani. >>> >>> >>> commit 8d409cb3e8a24196be7271defafd4638f3e0b514 >>> Author: Ville Syrjälä >>> Date: Wed Feb 10 19:59:05 2016 +0200 >>> >>> drm/i915: Fix hpd live status bits for g4x >>> >>> commit 3d8acd1f667b45c531401c8f0c2033072e32a05d >>> Author: Gary Wang >>> Date: Wed Dec 23 16:11:35 2015 +0800 >>> >>> drm/i915: increase the tries for HDMI hotplug live status checking >>> >>> commit 97f9010af05c15e0b7e6b4ef6ff8cb0ebb7e7715 >>> Author: Daniel Vetter >>> Date: Fri Dec 11 19:44:15 2015 +0100 >>> >>> drm/i915: mdelay(10) considered harmful >>> >>> commit 0f5a9be15797f78c9a34e432f26c796165b6e49a >>> Author: Imre Deak >>> Date: Fri Nov 27 18:55:29 2015 +0200 >>> >>> drm/i915: take a power domain reference while checking the HDMI live status >>> >>> >>> >>> > Hi Jani, > > Applying the following commit did indeed fix the original bug[0]: > > commit 8d409cb3e8a24196be7271defafd4638f3e0b514 > Author: Ville Syrjälä > Date: Wed Feb 10 19:59:05 2016 +0200 > > drm/i915: Fix hpd live status bits for g4x > > > > However, it also introduced a new bug, which is covered in that bug > report. The new bug is that after locking/unlocking the screen, all the > windows get shuffled around in a manner that is consistent with X > deciding that it's single-headed again, and then back to double headed. > This only happens when I build a kernel with both commit 237ed86c AND > commit 8d409cb3e. If I revert 237ed86c and keep only 8d409cb3e both the > original bug and the new bug go away. Do you think commit 237ed86c is > still even needed now that 8d409cb3e has landed? Maybe the new bug is > due to the interaction between 237ed86c and 8d409cb3e. > > Thanks, > > Joe > > [0] http://pad.lv/1543683 > > > > > Hello, Is there any addition debug data we can collect to debug the new bug that commit 8d409cb3e introduced? Thanks, Joe