[PATCH v1 5/5] drm: panel-backlight-quirks: Add Steam Decks

[Antheas Kapenekakis]

On Mon, 25 Aug 2025 at 18:47, Mario Limonciello
<mario.limonciello at amd.com> wrote:
>
> On 8/24/2025 3:02 PM, Antheas Kapenekakis wrote:
> > On the SteamOS kernel, Valve universally makes minimum brightness 0
> > for all devices. SteamOS is (was?) meant for the Steam Deck, so
> > enabling it universally is reasonable. However, it causes issues in
> > certain devices. Therefore, introduce it just for the Steam Deck here.
> >
> > SteamOS kernel does not have a public mirror, but this replaces commit
> > 806dd74bb225 ("amd/drm: override backlight min value from 12 -> 0")
> > in the latest, as of this writing, SteamOS kernel (6.11.11-valve24).
> > See unofficial mirror reconstructed from sources below.
> >
> > Link: https://gitlab.com/evlaV/linux-integration/-/commit/806dd74bb225
> > Signed-off-by: Antheas Kapenekakis <lkml at antheas.dev>
> > ---
>
> Directionally I agree with this commit in favor of what the downstream
> kernel tree has that you linked above.
>
> But I would rather see it sent alone and not tied to a series to
> overhaul how quirks work.  If it's sent alone we should be able to get
> it reviewed pretty easily and in drm-misc-fixes.

That's a good idea. However, this commit relies on patch 1 and 3, as
it has no edid information and uses a second match.

Antheas

> >   drivers/gpu/drm/drm_panel_backlight_quirks.c | 17 ++++++++++++++++-
> >   1 file changed, 16 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c
> > index 78c430b07d6a..5c24f4a86519 100644
> > --- a/drivers/gpu/drm/drm_panel_backlight_quirks.c
> > +++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c
> > @@ -73,7 +73,22 @@ static const struct drm_get_panel_backlight_quirk drm_panel_min_backlight_quirks
> >               .dmi_match_other.field = DMI_PRODUCT_NAME,
> >               .dmi_match_other.value = "ONEXPLAYER F1 EVA-02",
> >               .quirk = { .brightness_mask = 3, },
> > -     }
> > +     },
> > +     /* Steam Deck models */
> > +     {
> > +             .dmi_match.field = DMI_SYS_VENDOR,
> > +             .dmi_match.value = "Valve",
> > +             .dmi_match_other.field = DMI_PRODUCT_NAME,
> > +             .dmi_match_other.value = "Jupiter",
> > +             .quirk = { .min_brightness = 1, },
> > +     },
> > +     {
> > +             .dmi_match.field = DMI_SYS_VENDOR,
> > +             .dmi_match.value = "Valve",
> > +             .dmi_match_other.field = DMI_PRODUCT_NAME,
> > +             .dmi_match_other.value = "Galileo",
> > +             .quirk = { .min_brightness = 1, },
> > +     },
> >   };
> >
> >   static bool drm_panel_min_backlight_quirk_matches(
>
>