From mboxrd@z Thu Jan 1 00:00:00 1970 From: YH Huang Subject: Re: [PATCH v2] pwm-backlight: fix the panel power sequence Date: Thu, 22 Oct 2015 23:12:30 +0800 Message-ID: <1445526750.27586.8.camel@mtksdaap41> References: <1444987060-48202-1-git-send-email-yh.huang@mediatek.com> <1444988219.3541.3.camel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mailgw02.mediatek.com ([210.61.82.184]:39970 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1756693AbbJVPMe (ORCPT ); Thu, 22 Oct 2015 11:12:34 -0400 In-Reply-To: <1444988219.3541.3.camel@pengutronix.de> Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Philipp Zabel Cc: Thierry Reding , Jingoo Han , Lee Jones , Matthias Brugger , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Tomi Valkeinen , linux-mediatek@lists.infradead.org, Sascha Hauer , yingjoe.chen@mediatek.com, Jean-Christophe Plagniol-Villard , linux-arm-kernel@lists.infradead.org On Fri, 2015-10-16 at 11:36 +0200, Philipp Zabel wrote: > Am Freitag, den 16.10.2015, 17:17 +0800 schrieb YH Huang: > > In order to match the panel power sequence, disable the enable_gpio > > in the probe function. Also, reorder the code in the power_on and > > power_off function to match the timing. > > Could you also have a look at the "pwm-backlight: Avoid backlight > flicker when probed from DT" patch? > I think in case of a panel left enabled by the bootloader, your patch > will disable the backlight for a short time. > > best regards > Philipp > In the case of the panel disabled by the bootloader, your patch still has the following code and always enables the backlight in the probe function. pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", - GPIOD_OUT_HIGH); What do you think if I remove these two lines in my patch? if (pb->enable_gpio) gpiod_direction_output(pb->enable_gpio, 0); Regards, YH Huang