Re: [PATCH v2] soc: mediatek: Add deprecated compatible to mmsys

[Matthias Brugger]

On 01/12/2022 12:20, Chen-Yu Tsai wrote:
> On Mon, Nov 14, 2022 at 7:59 PM AngeloGioacchino Del Regno
> <angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
> > Il 11/11/22 09:29, matthias.bgg@xxxxxxxxxx ha scritto:
> > > From: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> > >
> > > For backward compatibility we add the deprecated compatible.
> > >
> > > Signed-off-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> >
> > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> >
> > ...And tested on MT8195 Cherry Chromebook.
>
> This now seems like a bad idea. In the dtsi we have two nodes (vdosys0 and
> vdosys1) that both currently use the -mmsys compatible, which in the driver
> maps to vdosys0. So not only do we have vdosys1 incorrectly probing as
> vdosys0, we also have duplicate clks being registered and duplicate DRM
> pipelines. On my device vdosys1 ends up winning the duplicate clock race.

That's true, we should fix the DTS deleting vdosys1 node as it's not 
implemented. While at it we should also fix the compatible for vdosys0 as 
"mediatek,mt8195-mmsys" is now deprecated.

Would you mind to send a patch?

Regards,
Matthias

> I suggest just reverting this. The display stuff won't be useful unless
> the drivers are able to distinguish themselves from one another.