Re: [PATCH] drm/edid: Dump the EDID when drm_edid_get_panel_id() has an error

From: Doug Anderson
Date: Mon Oct 24 2022 - 18:53:34 EST


Hi,

On Fri, Oct 21, 2022 at 2:18 PM Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
> Hi Doug
>
> On 10/21/2022 1:07 PM, Douglas Anderson wrote:
> > If we fail to get a valid panel ID in drm_edid_get_panel_id() we'd
> > like to see the EDID that was read so we have a chance of
> > understanding what's wrong. There's already a function for that, so
> > let's call it in the error case.
> >
> > NOTE: edid_block_read() has a retry loop in it, so actually we'll only
> > print the block read back from the final attempt. This still seems
> > better than nothing.
> >
> > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
>
> Instead of checkinf for edid_block_status_valid() on the base_block, do
> you want to use drm_edid_block_valid() instead?
>
> That way you get the edid_block_dump() for free if it was invalid.

I can... ...but it feels a bit awkward and maybe not quite how the
functions were intended to work together?

One thing I notice is that if I call drm_edid_block_valid() I'm doing
a bunch of duplicate work that already happened in edid_block_read(),
which already calls edid_block_check() and handles fixing headers. I
guess also if I call drm_edid_block_valid() then I should ignore the
"status" return value of edid_block_read() because we don't need to
pass it anywhere (because the work is re-done in
drm_edid_block_valid()).

So I guess I'm happy to do a v2 like that if everyone likes it better,
but to me it feels a little weird.

-Doug