diff mbox series

drm/panel: Document internal backlight handling

Message ID 20210715080017.239633-1-linus.walleij@linaro.org
State New
Headers show
Series drm/panel: Document internal backlight handling | expand

Commit Message

Linus Walleij July 15, 2021, 8 a.m. UTC
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(-)

-- 
2.31.1

Comments

Daniel Vetter July 15, 2021, 8:52 a.m. UTC | #1
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

>



-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
Doug Anderson July 15, 2021, 1:51 p.m. UTC | #2
Hi,

On Thu, Jul 15, 2021 at 1:02 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.


Can you rebase/post against drm-misc-next? If not then you'll conflict
with commit 10f7b40e4f30 ("drm/panel: add basic DP AUX backlight
support"). :-)

-Doug
diff mbox series

Patch

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.
 	 */
 	struct backlight_device *backlight;