[Intel-gfx] [PATCH] drm/i915: A better maximum brightness for users.

[Jani Nikula]

On Mon, 09 Nov 2015, "Shih-Yuan Lee (FourDollars)" <sylee at canonical.com> wrote:
> The PWM brightness level of Dell XPS 13 (2015) is from 10 to 937 however
> the sysfs brightness level always starts from 0 so it is better to use
> 927 as the sysfs maximum brightness level and it becomes easier to map
> from the PWM brightness level to the sysfs brightness level.

We've been thinking we should provide a fixed range to userspace
instead. Say, 0-100.

BR,
Jani.




>
> Signed-off-by: Shih-Yuan Lee (FourDollars) <sylee at canonical.com>
> ---
>  drivers/gpu/drm/i915/intel_panel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index a24df35..697fd4d 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -1211,7 +1211,7 @@ static int intel_backlight_device_register(struct intel_connector *connector)
>  	 * Note: Everything should work even if the backlight device max
>  	 * presented to the userspace is arbitrarily chosen.
>  	 */
> -	props.max_brightness = panel->backlight.max;
> +	props.max_brightness = panel->backlight.max - panel->backlight.min;
>  	props.brightness = scale_hw_to_user(connector,
>  					    panel->backlight.level,
>  					    props.max_brightness);

-- 
Jani Nikula, Intel Open Source Technology Center