On Wed, Aug 20, 2014 at 08:38:36AM +0200, Lothar Waßmann wrote:
> commit 257462dbf3ed ("pwm-backlight: switch to gpiod interface")
> introduced a regression leading to acquiring a bogus GPIO-0 when
> configured from DT without an 'enable-gpios' property.
> The driver will happily accept the 0 initialized 'enable_gpio' member
> of the struct platform_pwm_backlight_data as valid gpio number, and
> request this GPIO as enable pin. In case of multiple driver instances,
> the second will fail to register with the error message:
> pwm-backlight backlight1.23: failed to request GPIO#0: -16
>
> Fix this by setting enable_gpio in the pdata struct to -EINVAL.
>
> Signed-off-by: Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/video/backlight/pwm_bl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index d7a3d13..e6ef6b4 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -172,7 +172,7 @@ static int pwm_backlight_parse_dt(struct device *dev,
> data->dft_brightness = value;
> data->max_brightness--;
> }
> -
> + data->enable_gpio = -EINVAL;
I'd prefer to keep the blank line for readability. Other than that:
Acked-by: Thierry Reding <treding@xxxxxxxxxx>
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