Re: [PATCH v1] drm/edid: add 6 bpc quirk to the Sharp LQ116M1JW10

[Doug Anderson]

Hi,

On Fri, Oct 31, 2025 at 3:40 AM Jani Nikula <jani.nikula@xxxxxxxxx> wrote:
>
> On Fri, 31 Oct 2025, Jani Nikula <jani.nikula@xxxxxxxxx> wrote:
> > On Thu, 30 Oct 2025, Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> >> Hi,
> >>
> >> On Thu, Oct 30, 2025 at 2:44 AM Ajye Huang
> >> <ajye_huang@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >>>
> >>> The Sharp LQ116M1JW105 reports that it supports 8 bpc modes,
> >>> but it will happen display noise in some videos.
> >>> So, limit it to 6 bpc modes.
> >>>
> >>> Signed-off-by: Ajye Huang <ajye_huang@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
> >>> ---
> >>>  drivers/gpu/drm/drm_edid.c | 3 +++
> >>>  1 file changed, 3 insertions(+)
> >>>
> >>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> >>> index e2e85345aa9a..a73d37fe7ea1 100644
> >>> --- a/drivers/gpu/drm/drm_edid.c
> >>> +++ b/drivers/gpu/drm/drm_edid.c
> >>> @@ -250,6 +250,9 @@ static const struct edid_quirk {
> >>>         EDID_QUIRK('S', 'V', 'R', 0x1019, BIT(EDID_QUIRK_NON_DESKTOP)),
> >>>         EDID_QUIRK('A', 'U', 'O', 0x1111, BIT(EDID_QUIRK_NON_DESKTOP)),
> >>>
> >>> +       /* LQ116M1JW10 displays noise when 8 bpc, but display fine as 6 bpc */
> >>> +       EDID_QUIRK('S', 'H', 'P', 0x154c, EDID_QUIRK_FORCE_6BPC),
> >>
> >> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> >
> > FWIW,
> >
> > Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>
> And as soon as I hit send, I notice the quirk is missing BIT(). It's a
> bit mask, and the enum signifies the bit number.

Crud, that's not good! Sorry for missing that. :( Definitely glad you noticed!

>From off-list communication, it sounds like there is still some
digging going on to see what's really happening with this panel, too.
There is still some sort of mystery...


-Doug