From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754902Ab0AODgX (ORCPT ); Thu, 14 Jan 2010 22:36:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753332Ab0AODgW (ORCPT ); Thu, 14 Jan 2010 22:36:22 -0500 Received: from gate.crashing.org ([63.228.1.57]:41346 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753116Ab0AODgW (ORCPT ); Thu, 14 Jan 2010 22:36:22 -0500 Subject: Re: drm/radeon/kms: fix up LVDS handling on macs (v2) From: Benjamin Herrenschmidt To: Michel =?ISO-8859-1?Q?D=E4nzer?= Cc: Alex Deucher , Linux Kernel Mailing List , Dave Airlie In-Reply-To: <1263463781.3544.4714.camel@thor> References: <201001140059.o0E0x4wS006650@hera.kernel.org> <1263437142.724.320.camel@pasglop> <1263463781.3544.4714.camel@thor> Content-Type: text/plain; charset="UTF-8" Date: Fri, 15 Jan 2010 14:35:56 +1100 Message-ID: <1263526556.724.402.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2010-01-14 at 11:09 +0100, Michel Dänzer wrote: > I have looked at radeonfb for a patch I posted a while ago to expose a > backlight class device with KMS, and I can only see what you describe > above affecting the LVDS_GEN_CNTL backlight level, not BLON or > BL_MOD_EN. Am I missing something? No, you aren't, it's radeonfb who is :-) I never quite got that part right. I was somewhat hoping several times that Hui and then Alex would manage to dig some info from ATI about what the right method is to drive those panels I think :-) But my observation on those HW was definitely that when inverted, disabling the modulation was also turning the panel to full bright on, rather than turning it off. > Without my patch, KMS doesn't change the backlight level at all, so > assuming the firmware manages to enable the backlight, it should stay > like that. Your patch might make things better than they are today, I'm not arguing there :-) I'm just saying that now might be a good time to try to sort out exactly what should be done in there :-) Cheers, Ben.