From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Isely <isely@isely.net>
Subject: Re: [PATCH 2/2] drm/i915/lvds: Use
 i915.lvds_fixed_mode= as a last resort
Date: Wed, 20 Apr 2011 15:09:27 -0500 (CDT)
Message-ID: <alpine.DEB.1.10.1104201458440.31843@cnc.isely.net>
References: <1303022613-18414-1-git-send-email-chris@chris-wilson.co.uk>
	<1303022613-18414-2-git-send-email-chris@chris-wilson.co.uk>
	<alpine.DEB.1.10.1104201419170.31843@cnc.isely.net>
	<b7da2f$r640mo@fmsmga001.fm.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org>
Received: from cnc.isely.net (cnc.isely.net [75.149.91.89])
	by gabe.freedesktop.org (Postfix) with ESMTP id 7A9A39E70A
	for <intel-gfx@lists.freedesktop.org>;
	Wed, 20 Apr 2011 13:09:28 -0700 (PDT)
In-Reply-To: <b7da2f$r640mo@fmsmga001.fm.intel.com>
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/intel-gfx>
List-Post: <mailto:intel-gfx@lists.freedesktop.org>
List-Help: <mailto:intel-gfx-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=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: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Airlied <airlied@linux.ie>, intel-gfx@lists.freedesktop.org
List-Id: intel-gfx@lists.freedesktop.org

On Wed, 20 Apr 2011, Chris Wilson wrote:

> On Wed, 20 Apr 2011 14:48:36 -0500 (CDT), Mike Isely <isely@isely.net> wrote:
> > 
> > Chris:
> > 
> > I've tested this patch and it doesn't help us here.  Even if I add 
> > lvds_fixed_mode=<whatever>, the display still comes up with the messed 
> > up configuration from the motherboard's completely ignorant BIOS.  It 
> > appears that lvds_fixed_mode is being ignored by the driver.
> 
> You can test the functionality of the patch by parsing
> i915.lvds_fixed_mode first rather than last.

I will test for that - it was the next thing I was going to dig into.


> 
> Then I just have to weigh up the wishes of Dave who has hordes of users
> desperate to fry their hardware, versus the tiny number who truly need
> an override and know what they are doing...

I understand your sentiment here.  But please also consider that this 
same feature existed on the UMS side for 3 years and I don't remember 
hearing about any flood of fried hardware because of it...

And really, this should be all about making legitimate capabilities 
available, not deliberately blocking them.

A good compromise, if this is really viewed as a legitimate problem 
(which I don't think it should be), would be to add an "I know what I'm 
doing, darnit" switch to the driver which would enable potentially 
hazardous tweaks.  Then one can hang all the "here there be dragons", 
"do not enter", "don't blame me for frying your hardware", etc caveats 
and warnings onto that switch...

  -Mike


-- 

Mike Isely
isely @ isely (dot) net
PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8