Re: [PATCH v3] arm64: dts: mt8173: Fix elm panel DT node

[Pin-yen Lin <treapking@chromium.org>]

All we know is that the functions mentioned in the commit message were
working in 4.19 kernel, but not in the latest kernel tree.

Unfortunately, we don't know which patch breaks the driver.

Best regards,
Pin-yen

On Thu, Jul 7, 2022 at 10:50 PM Matthias Brugger <matthias.bgg@gmail.com> wrote:
>
>
>
> On 21/06/2022 11:18, Pin-Yen Lin wrote:
> > Move the panel DT node under `aux-bus` node, so it won't use the buggy
> > `ps8640_bridge_get_edid` to get the display modes. Also, change the
> > compatible string from "lg,lp120up1" to "edp-panel", so the panel-edp
> > driver gets the displays modes from the EDID instead of using the
> > predefined display mode (`lg_lp129qe_mode`) in the driver, which is
> > actually not working.
> >
>
> Do we need a fixes tag here? I'm not quite sure if we fix an upstream bug here,
> to be honest.
>
> Regards,
> Matthias
>
> > Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
> > ---
> >
> > Changes in v3:
> > - Include more details in the commit message.
> >
> > Changes in v2:
> > - Remove the Fixes tag because this change is not compatible with the
> >    old kernel versions.
> >
> >   arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 26 +++++++++++---------
> >   1 file changed, 14 insertions(+), 12 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> > index 9c75fbb31f98..1e0802a6f6d2 100644
> > --- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> > @@ -90,18 +90,6 @@ volume_up {
> >               };
> >       };
> >
> > -     panel: panel {
> > -             compatible = "lg,lp120up1";
> > -             power-supply = <&panel_fixed_3v3>;
> > -             backlight = <&backlight>;
> > -
> > -             port {
> > -                     panel_in: endpoint {
> > -                             remote-endpoint = <&ps8640_out>;
> > -                     };
> > -             };
> > -     };
> > -
> >       panel_fixed_3v3: regulator1 {
> >               compatible = "regulator-fixed";
> >               regulator-name = "PANEL_3V3";
> > @@ -282,6 +270,20 @@ ps8640_out: endpoint {
> >                               };
> >                       };
> >               };
> > +
> > +             aux-bus {
> > +                     panel {
> > +                             compatible = "edp-panel";
> > +                             power-supply = <&panel_fixed_3v3>;
> > +                             backlight = <&backlight>;
> > +
> > +                             port {
> > +                                     panel_in: endpoint {
> > +                                             remote-endpoint = <&ps8640_out>;
> > +                                     };
> > +                             };
> > +                     };
> > +             };
> >       };
> >   };
> >