Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753623Ab2HCQZA (ORCPT ); Fri, 3 Aug 2012 12:25:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43430 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752188Ab2HCQY7 (ORCPT ); Fri, 3 Aug 2012 12:24:59 -0400 Date: Fri, 3 Aug 2012 11:24:51 -0500 From: Seth Forshee To: Matthew Garrett Cc: dri-devel@lists.freedesktop.org, Daniel Vetter , David Airlie , linux-kernel@vger.kernel.org, Andreas Heider Subject: Re: [RFC PATCH 3/5] drm/i915: register LVDS connector even if we can't get a panel mode Message-ID: <20120803162451.GF8165@thinkpad-t410> Mail-Followup-To: Matthew Garrett , dri-devel@lists.freedesktop.org, Daniel Vetter , David Airlie , linux-kernel@vger.kernel.org, Andreas Heider References: <1344009741-14248-1-git-send-email-seth.forshee@canonical.com> <1344009741-14248-4-git-send-email-seth.forshee@canonical.com> <20120803161416.GA22563@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120803161416.GA22563@srcf.ucam.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1352 Lines: 28 On Fri, Aug 03, 2012 at 05:14:16PM +0100, Matthew Garrett wrote: > On Fri, Aug 03, 2012 at 11:02:19AM -0500, Seth Forshee wrote: > > Some Apple hybrid graphics machines do not have the LVDS panel connected > > to the integrated GPU at boot and also do not supply a VBT. The LVDS > > connector is not registered as a result, making it impossible to support > > graphics switching. > > > > This patch changes intel_lvds_init() to register the connector even if > > we can't find any panel modes. This makes it necessary to always check > > intel_lvds->fixed_mode before use, as it could now be NULL. > > This one kind of sucks. I think adding a quirk for this situation would > be justifiable, rather than doing it for all devices. This is one of the things I wasn't so sure about. There are various checks in intel_lvds_init() that can cause it to bail out before we try to get the EDID, and I don't fully understand all of them. If non-laptop machines are expected to bail out before the EDID check then the approach I've taken seems reasonable. Otherwise adding a quirk probably is a good idea. Seth -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/