[PATCH] video: backlight: Drop maximum brightness override for brightness zero

[Noralf Trønnes]

Den 09.07.2021 15.26, skrev Marek Vasut:
> The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper
> in backlight.c") says that gpio-backlight uses brightness as power state.
> This has been fixed since in ec665b756e6f7 ("backlight: gpio-backlight:
> Correct initial power state handling") and other backlight drivers do not
> require this workaround. Drop the workaround.
> 
> This fixes the case where e.g. pwm-backlight can perfectly well be set to
> brightness 0 on boot in DT, which without this patch leads to the display
> brightness to be max instead of off.
> 
> Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c")

I not sure about the rules, but if this is automatically picked up for
stable, maybe this is needed to avoid changing behaviour on 4.19:

Cc: <stable at vger.kernel.org> # 5.4+

of_find_backlight() was added in 4.17 and the gpio fix in 5.4.

Or perhaps there are other ways to signal this dependency.

> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Daniel Thompson <daniel.thompson at linaro.org>
> Cc: Meghana Madhyastha <meghana.madhyastha at gmail.com>
> Cc: Noralf Trønnes <noralf at tronnes.org>
> Cc: Sean Paul <seanpaul at chromium.org>
> Cc: Thierry Reding <treding at nvidia.com>
> ---

Acked-by: Noralf Trønnes <noralf at tronnes.org>