2023-07-21 10:58:44

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v4] backlight: gpio_backlight: Drop output GPIO direction check for initial power state

On Fri, Jul 21, 2023 at 09:29:03AM +0000, Ying Liu wrote:
> If GPIO pin is in input state but backlight is currently off due to
> default pull downs, then initial power state is set to FB_BLANK_UNBLANK
> in DT boot mode with phandle link and the backlight is effectively
> turned on in gpio_backlight_probe(), which is undesirable according to
> patch description of commit ec665b756e6f ("backlight: gpio-backlight:
> Correct initial power state handling").
>
> Quote:
> ---8<---
> If in DT boot we have phandle link then leave the GPIO in a state which the
> bootloader left it and let the user of the backlight to configure it further.
> ---8<---
>
> So, let's drop output GPIO direction check and only check GPIO value to set
> the initial power state.

LGTM,
Reviewed-by: Andy Shevchenko <[email protected]>

--
With Best Regards,
Andy Shevchenko