[PATCH] drm/panel: Document internal backlight handling

[Daniel Vetter]

On Thu, Jul 15, 2021 at 10:02 AM Linus Walleij <linus.walleij at linaro.org> wrote:
>
> Panels with internal backlight need to assign their backlight member
> directly.
>
> Reported-by: Doug Anderson <dianders at chromium.org>
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> ---
>  include/drm/drm_panel.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
> index 33605c3f0eba..1e63fadf1368 100644
> --- a/include/drm/drm_panel.h
> +++ b/include/drm/drm_panel.h
> @@ -144,8 +144,9 @@ struct drm_panel {
>          * Backlight device, used to turn on backlight after the call
>          * to enable(), and to turn off backlight before the call to
>          * disable().
> -        * backlight is set by drm_panel_of_backlight() and drivers
> -        * shall not assign it.
> +        * External backlight is assigned by drm_panel_of_backlight() while
> +        * panel-internal backlight is assigned directly to this member by the
> +        * panel driver.

External/internal feels a bit like imprecise wording. Maybe something like

drm_panel_of_backlight() automatically sets this, drivers which obtain
their backlight through some other means need to explicitly set this
themselves.

And then perhaps also update the kerneldoc for drm_panel_of_backlight?

Maybe in the future we'll have some similar helpers for acpi or the
backlight on dp aux or whatever might happen with hardware.

Either way: Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Because updating and clarifying docs is always great!
-Daniel

>          */
>         struct backlight_device *backlight;
>
> --
> 2.31.1
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch