Re: [PATCH 2/2] backlight: pwm_bl: Check the pwm state for initial backlight power state

From: Lee Jones
Date: Wed Oct 26 2016 - 08:11:02 EST


On Fri, 30 Sep 2016, Peter Ujfalusi wrote:

> If the pwm is not enabled the backlight initially should not be enabled
> either if we have booted with DT and there is a phandle pointing to the
> backlight node.
>
> The patch extends the checks to decide if we should keep the backlight off
> initially.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
> drivers/video/backlight/pwm_bl.c | 4 ++++
> 1 file changed, 4 insertions(+)

Makes sense to me.

I'm going to apply this until someone screams at me.

> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 9bc4715bf116..e4326bbf807f 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -223,6 +223,10 @@ static int pwm_backlight_initial_power_state(const struct pwm_bl_data *pb)
> if (!regulator_is_enabled(pb->power_supply))
> return FB_BLANK_POWERDOWN;
>
> + /* The pwm is disabled, keep it like this */
> + if (!pwm_is_enabled(pb->pwm))
> + return FB_BLANK_POWERDOWN;
> +
> return FB_BLANK_UNBLANK;
> }
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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