From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Date: Tue, 03 Nov 2015 11:08:44 +0000 Subject: Re: [PATCH v2] pwm-backlight: fix the panel power sequence Message-Id: <1446548924.3373.3.camel@pengutronix.de> List-Id: References: <1444987060-48202-1-git-send-email-yh.huang@mediatek.com> <1444988219.3541.3.camel@pengutronix.de> <1445526750.27586.8.camel@mtksdaap41> <1446133259.3274.52.camel@pengutronix.de> <1446190900.17558.16.camel@mtksdaap41> <1446201271.3334.22.camel@pengutronix.de> <1446538299.2449.8.camel@mtksdaap41> In-Reply-To: <1446538299.2449.8.camel@mtksdaap41> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hi YH, Am Dienstag, den 03.11.2015, 16:11 +0800 schrieb YH Huang: > > The reasoning is that devices where there is no phandle link pointing to > > the backlight (for example from a simple-panel node), we should keep the > > current default behaviour (enable during probe). > > I have a little problem for the current default behaviour. > Should we enable during probe? Here I mean enabling the backlight (at the end of the probe function), not enabling the GPIO already when requesting it. > Before this patch ( http://patchwork.ozlabs.org/patch/324690/ ), > we disable "enable-gpio" in the probe function. While before this patch the GPIO would be initialized in the disabled state, the call to backlight_update_status at the end of the probe function would still enable the backlight afterwards. regards Philipp