On Fri, Jul 09, 2021 at 03:53:16PM +0200, Noralf Trønnes wrote:
>
>
> 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:
>
>
> 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.
Agree we need to make sure the Fixes: tag doesn't provoke regressions
in v4.19.
Is this the syntax appropriate?
Cc: <stable@xxxxxxxxxxxxxxx> # 5.4+
Cc: <stable@xxxxxxxxxxxxxxx> # 4.19.x: ec665b756e6f7: backlight: gpio-backlight: Correct initial power state handling
> > Signed-off-by: Marek Vasut <marex@xxxxxxx>
> > Cc: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> > Cc: Meghana Madhyastha <meghana.madhyastha@xxxxxxxxx>
> > Cc: Noralf Trønnes <noralf@xxxxxxxxxxx>
> > Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
> > Cc: Thierry Reding <treding@xxxxxxxxxx>
> > ---
>
> Acked-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
With the above (or something similar to avoid problems with v4.19):
Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Daniel.
