Messages in this thread | | | Subject | Re: [PATCH v2] pwm-backlight: fix the panel power sequence | From | YH Huang <> | Date | Tue, 3 Nov 2015 16:11:39 +0800 |
| |
On Fri, 2015-10-30 at 11:34 +0100, Philipp Zabel wrote: > Am Freitag, den 30.10.2015, 15:41 +0800 schrieb YH Huang: > > > That won't work if the gpio is still configured as input. How about I > > > add the GPIOD_ASIS change to my patch you remove that and the above from > > > yours? > > > > I revise these two lines > > if (pb->enable_gpio) > > gpiod_direction_output(pb->enable_gpio, 0); > > into > > if (pb->enable_gpio) { > > if(gpiod_get_value(pb->enable_gpio) == 0) > > gpiod_direction_output(pb->enable_gpio, 0); > > else > > gpiod_direction_output(pb->enable_gpio, 1); > > } > > If the GPIO is still configured as an input, the return value of > gpiod_get_value could be random. > > > I am not sure what "phandle" is working for. > > 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?
Before this patch ( http://patchwork.ozlabs.org/patch/324690/ ), we disable "enable-gpio" in the probe function.
Do you have any idea of this?
Regards, YH Huang
| |