From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Subject: RE: [PATCH 1/2] OMAP3EVM: Made backlight GPIO default state to off Date: Thu, 01 Apr 2010 16:32:34 +0300 Message-ID: <1270128754.2704.107.camel@tubuntu.research.nokia.com> References: <1269263470-13814-1-git-send-email-hvaibhav@ti.com> <1270122886.2704.100.camel@tubuntu.research.nokia.com> <19F8576C6E063C45BE387C64729E7394044DF7EF68@dbde02.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nokia.com ([192.100.122.233]:29402 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751744Ab0DANcw (ORCPT ); Thu, 1 Apr 2010 09:32:52 -0400 In-Reply-To: <19F8576C6E063C45BE387C64729E7394044DF7EF68@dbde02.ent.ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "ext Hiremath, Vaibhav" Cc: "linux-omap@vger.kernel.org" , "tony@atomide.com" On Thu, 2010-04-01 at 14:11 +0200, ext Hiremath, Vaibhav wrote: > > -----Original Message----- > > From: Tomi Valkeinen [mailto:tomi.valkeinen@nokia.com] > > Sent: Thursday, April 01, 2010 5:25 PM > > To: Hiremath, Vaibhav > > Cc: linux-omap@vger.kernel.org; tony@atomide.com > > Subject: Re: [PATCH 1/2] OMAP3EVM: Made backlight GPIO default state to off > > > > Hi, > > > > On Mon, 2010-03-22 at 14:11 +0100, ext hvaibhav@ti.com wrote: > > > From: Vaibhav Hiremath > > > > > > If you choose default output to DVI, the LCD backlight still > > > gets powered, since panel->disable function never gets called for LCD. > > > > > > So, during init put backlight GPIO to off state and the driverr > > > code will decide which output to enable explicitly. > > > > I'm not sure I understand this patch. You talk about choosing default > > output (via kernel boot args, I presume), > [Hiremath, Vaibhav] yes you are correct. I am talking about default output selection using bootargs. > > > but the code checks for EVM > > revision. What is the connection between EVM revision and selecting > > display output? > [Hiremath, Vaibhav] Ohh ok, I think you are not aware that we do have 2 version of EVM's. EVM-1 with positive (backlight gpio) polarity and EVM-2 with negative (backlight gpio) polarity. > > The code is doing exactly same. Ok. But I still don't understand the relation with the patch comment, and the code. Shouldn't you anyway initialize the backlight gpio properly depending on the EVM revision, no matter if DVI is the default output or not? Perhaps the comment could be clarified. But the code looks fine: Acked-by: Tomi Valkeinen Tomi