On Thu, Oct 26, 2023 at 3:53 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Add a comment explaining that acpi_video_backlight_use_native() MUST
> only be used by GPU drivers and that it must NOT be used on other places.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> The main reason for writing this patch is that some recent submitted
> patches actually were using acpi_video_backlight_use_native() wrong.
> ---
> include/acpi/video.h | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/include/acpi/video.h b/include/acpi/video.h
> index 4230392b5b0b..3d538d4178ab 100644
> --- a/include/acpi/video.h
> +++ b/include/acpi/video.h
> @@ -75,6 +75,15 @@ static inline enum acpi_backlight_type acpi_video_get_backlight_type(void)
> return __acpi_video_get_backlight_type(false, NULL);
> }
>
> +/*
> + * This function MUST only be called by GPU drivers to check if the driver
> + * should register a backlight class device. This function not only checks
> + * if a GPU native backlight device should be registered it *also* tells
> + * the ACPI video-detect code that native GPU backlight control is available.
> + * Therefor calling this from any place other then the GPU driver is wrong!
> + * To check if GPU native backlight control is used in other places instead use:
> + * if (acpi_video_get_backlight_type() == acpi_backlight_native) { ... }
> + */
> static inline bool acpi_video_backlight_use_native(void)
> {
> return __acpi_video_get_backlight_type(true, NULL) == acpi_backlight_native;
> --
Applied as 6.8 material, thanks!
