On Thu, Jul 15, 2021 at 10:02 AM Linus Walleij linus.walleij@linaro.org wrote:

Panels with internal backlight need to assign their backlight member directly.

Reported-by: Doug Anderson dianders@chromium.org Signed-off-by: Linus Walleij linus.walleij@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@ffwll.ch

Because updating and clarifying docs is always great! -Daniel

     */
    struct backlight_device *backlight;

-- 2.31.1