On Tue, Dec 21, 2021 at 06:47:31PM +0300, Dmitry Osipenko wrote:
> 21.12.2021 13:58, Thierry Reding пишет:
> ..
> >>>> The panel->ddc isn't used by the new panel-edp driver unless panel is
> >>>> compatible with "edp-panel". Hence the generic_edp_panel_probe() should
> >>>> either fail or crash for a such "edp-panel" since panel->ddc isn't fully
> >>>> instantiated, AFAICS.
> >>>
> >>> I've tested this and it works fine on Venice 2. Since that was the
> >>> reference design for Nyan, I suspect that Nyan's will also work.
> >>>
> >>> It'd be great if Thomas or anyone else with access to a Nyan could
> >>> test this to verify that.
> >>
> >> There is no panel-edp driver in the v5.15. The EOL of v5.15 is Oct,
> >> 2023, hence we need to either use:
> > 
> > All the (at least relevant) functionality that is in panel-edp was in
> > panel-simple before it was moved to panel-edp. I've backported this set
> > of patches to v5.15 and it works just fine there.
> 
> Will we be able to add patch to bypass the panel's DT ddc-i2c-bus on
> Nyan to keep the older DTBs working?

I don't see why we would want to do that. It's quite clear that the DTB
is buggy in this case and we have a more accurate way to describe what's
really there in hardware. In addition that more accurate representation
also gets rid of a bug. Obviously because the bug is caused by the
previous representation that was not accurate.

Given that we can easily replace the DTBs on these devices there's no
reason to make this any more complicated than it has to be.

Thierry