Re: [PATCH] ACPI: video: force native backlight on Acer Nitro AN515-46

On Mon, Jul 27, 2026 at 3:22 PM Marcos Paulo Medeiros
<[email protected]> wrote:
>
> The Acer Nitro AN515-46 is a hybrid graphics laptop whose internal
> panel is driven by the AMD GPU (Radeon 680M); the discrete NVIDIA GPU
> only drives external outputs. The firmware nevertheless advertises the
> NVIDIA WMI EC backlight GUID, so the backlight type resolves to
> nvidia_wmi_ec. The nvidia-wmi-ec-backlight driver however fails to
> probe ("EC backlight control failed: AE_NOT_FOUND") and, since the
> backlight type is still nvidia_wmi_ec, amdgpu skips registering its
> own backlight device. The result is no backlight device at all,
> leaving the brightness keys and the desktop brightness slider
> non-functional.
>
> Booting with acpi_backlight=native makes amdgpu register its backlight
> interface and brightness control works. Add a DMI quirk to use the
> native backlight on this model by default.
>
> Signed-off-by: Marcos Paulo Medeiros <[email protected]>
> ---
>  drivers/acpi/video_detect.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
> index 5b0dc679e..07755b856 100644
> --- a/drivers/acpi/video_detect.c
> +++ b/drivers/acpi/video_detect.c
> @@ -919,6 +919,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
>                 DMI_MATCH(DMI_PRODUCT_NAME, "OMEN by HP Gaming Laptop 16-n0xxx"),
>                 },
>         },
> +       {
> +        .callback = video_detect_force_native,
> +        /* Acer Nitro AN515-46 */
> +        .matches = {
> +               DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +               DMI_MATCH(DMI_PRODUCT_NAME, "Nitro AN515-46"),
> +               },
> +       },
>
>         /*
>          * x86 android tablets which directly control the backlight through
> --

Applied as 7.3 material, thanks!