From mboxrd@z Thu Jan 1 00:00:00 1970 From: yh.huang@mediatek.com (YH Huang) Date: Fri, 6 Nov 2015 16:31:30 +0800 Subject: [PATCH v2] pwm-backlight: fix the panel power sequence In-Reply-To: <1446716430.3894.12.camel@pengutronix.de> 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> <1446548924.3373.3.camel@pengutronix.de> <1446601656.15340.11.camel@mtksdaap41> <1446716430.3894.12.camel@pengutronix.de> Message-ID: <1446798690.6203.3.camel@mtksdaap41> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 2015-11-05 at 10:40 +0100, Philipp Zabel wrote: > > > > Based on this, could we disable it initially and update in the > > backlight_update_status function? > > > > Like this, > > > > if (pb->enable_gpio) { > > if (phandle && > > gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_OUT && > > gpiod_get_value(pb->enable_gpio) == 1) > > gpiod_direction_output(pb->enable_gpio, 1); > > The gpiod_direction_output call is a no-op, since the direction is > already output and the value is already 1. > Also, I propose to set initial blanking to FB_BLANK_POWERDOWN in this > case, and wait for the panel driver to enable the backlight at the > appropriate time. Thanks your kindly reply. Your patch looks good to me. Regards, YH Huang