From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753422AbcB2JeK (ORCPT <rfc822;w@1wt.eu>);
	Mon, 29 Feb 2016 04:34:10 -0500
Received: from mga09.intel.com ([134.134.136.24]:41189 "EHLO mga09.intel.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752689AbcB2JeF convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 29 Feb 2016 04:34:05 -0500
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.22,520,1449561600"; 
   d="scan'208";a="926059884"
From: Jani Nikula <jani.nikula@linux.intel.com>
To: Joseph Salisbury <joseph.salisbury@canonical.com>, sonika.jindal@intel.com
Cc: shashank.sharma@intel.com, rodrigo.vivi@intel.com,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        intel-gfx <intel-gfx@lists.freedesktop.org>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid
In-Reply-To: <56CE22DB.6050108@canonical.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
References: <56CE22DB.6050108@canonical.com>
User-Agent: Notmuch/0.21+34~g7dd0d52 (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu)
Date: Mon, 29 Feb 2016 11:33:59 +0200
Message-ID: <87lh63uago.fsf@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 24 Feb 2016, Joseph Salisbury <joseph.salisbury@canonical.com> 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 <sonika.jindal@intel.com>
> 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?

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 <ville.syrjala@linux.intel.com>
Date:   Wed Feb 10 19:59:05 2016 +0200

    drm/i915: Fix hpd live status bits for g4x

commit 3d8acd1f667b45c531401c8f0c2033072e32a05d
Author: Gary Wang <gary.c.wang@intel.com>
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 <daniel.vetter@ffwll.ch>
Date:   Fri Dec 11 19:44:15 2015 +0100

    drm/i915: mdelay(10) considered harmful

commit 0f5a9be15797f78c9a34e432f26c796165b6e49a
Author: Imre Deak <imre.deak@intel.com>
Date:   Fri Nov 27 18:55:29 2015 +0200

    drm/i915: take a power domain reference while checking the HDMI live status




-- 
Jani Nikula, Intel Open Source Technology Center