Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755314Ab2HEXUd (ORCPT ); Sun, 5 Aug 2012 19:20:33 -0400 Received: from mail-wg0-f44.google.com ([74.125.82.44]:39378 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755207Ab2HEXUc (ORCPT ); Sun, 5 Aug 2012 19:20:32 -0400 MIME-Version: 1.0 In-Reply-To: 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> <20120803162451.GF8165@thinkpad-t410> <20120803162702.GA22896@srcf.ucam.org> <20120804165727.GA4980@thinkpad-t410> <20120805211412.GG12232@phenom.ffwll.local> <20120805211838.GA27188@srcf.ucam.org> <20120805214016.GH12232@phenom.ffwll.local> Date: Sun, 5 Aug 2012 19:20:31 -0400 Message-ID: Subject: Re: [RFC PATCH 3/5] drm/i915: register LVDS connector even if we can't get a panel mode From: Alex Deucher To: Dave Airlie Cc: Matthew Garrett , dri-devel@lists.freedesktop.org, David Airlie , linux-kernel@vger.kernel.org, Andreas Heider Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2113 Lines: 42 On Sun, Aug 5, 2012 at 5:44 PM, Dave Airlie wrote: > On Mon, Aug 6, 2012 at 7:40 AM, Daniel Vetter wrote: >> On Sun, Aug 05, 2012 at 10:18:38PM +0100, Matthew Garrett wrote: >>> On Sun, Aug 05, 2012 at 11:14:12PM +0200, Daniel Vetter wrote: >>> >>> > I like this approach more - the only other solution I see is to ask the >>> > currently active driver (i.e. radeon) at bootime for the right mode. Which >>> > sounds much more hellish and fragile ... >>> >>> The "correct" approach is clearly to just have the drm core change the >>> i2c mux before requesting edid, but that's made difficult because of the >>> absence of ordering guarantees in initialisation. I don't like quirking >>> this, since we're then back to the situation of potentially having to >>> add every new piece of related hardware to the quirk list. >> >> The "correct" approach of switching the mux before we fetch the edid is >> actualy the one I fear will result in fragile code: Only run on few >> machines, and as you say with tons of funky interactions with the init >> sequence ordering. And I guess people will bitch&moan about the flickering >> this will cause ;-) >> >> As long as it's only apple shipping multi-gpu machines with >> broken/non-existing vbt, I'll happily stomach the quirk list entries. >> They're bad, but imo the lesser evil. > > Well in theory you can switch the ddc lines without switching the other lines, > so we could do a mutex protected mux switch around edid retrival, > Depends on the system. On non-Macs, some systems have a single mux, others have a separate mux for i2c and display as specified in the ATPX ACPI methods. Not sure how the Macs do it. I've started cleaning up the PX radeon code along with a bunch of other radeon ralated ACPI fixes: http://cgit.freedesktop.org/~agd5f/linux/log/?h=acpi_patches Alex -- 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/