Re: [PATCH V2] video: backlight: Drop maximum brightness override for brightness zero

[Lee Jones <lee.jones@linaro.org>]

On Sat, 11 Sep 2021, Marek Vasut wrote:

> On 7/13/21 9:16 PM, Marek Vasut wrote:
> > 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")
> > Acked-by: Noralf Trønnes <noralf@tronnes.org>
> > Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> > Cc: <stable@vger.kernel.org> # 5.4+
> > Cc: <stable@vger.kernel.org> # 4.19.x: ec665b756e6f7: backlight: gpio-backlight: Correct initial power state handling
> > Signed-off-by: Marek Vasut <marex@denx.de>
> > Cc: Daniel Thompson <daniel.thompson@linaro.org>
> > Cc: Meghana Madhyastha <meghana.madhyastha@gmail.com>
> > Cc: Noralf Trønnes <noralf@tronnes.org>
> > Cc: Sean Paul <seanpaul@chromium.org>
> > Cc: Thierry Reding <treding@nvidia.com>
> > ---
> > V2: Add AB/RB, CC stable
> > ---
> >   drivers/video/backlight/backlight.c | 6 ------
> >   1 file changed, 6 deletions(-)
> > 
> > diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
> > index 537fe1b376ad7..fc990e576340b 100644
> > --- a/drivers/video/backlight/backlight.c
> > +++ b/drivers/video/backlight/backlight.c
> > @@ -688,12 +688,6 @@ static struct backlight_device *of_find_backlight(struct device *dev)
> >   			of_node_put(np);
> >   			if (!bd)
> >   				return ERR_PTR(-EPROBE_DEFER);
> > -			/*
> > -			 * Note: gpio_backlight uses brightness as
> > -			 * power state during probe
> > -			 */
> > -			if (!bd->props.brightness)
> > -				bd->props.brightness = bd->props.max_brightness;
> >   		}
> >   	}
> > 
> 
> Any news on this ?
> 
> Expanding CC list.

Looks like I was left off of the original submission.

I can't apply a quoted patch.  Please re-submit.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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