[Intel-gfx] [PATCH] drm: Silence zero EDID carping

[Chris Wilson]

Quoting Ville Syrjälä (2020-10-29 14:07:46)
> On Thu, Oct 29, 2020 at 11:00:30AM +0000, Chris Wilson wrote:
> > We have a few displays in CI that always report their EDID as a bunch of
> > zeroes. This is consistent behavioud, so one assumes intentional
> > indication of an "absent" EDID. Let us treat is as such by silently
> > reporting the zero edid using connector->null_edid_counter, leaving the
> > loud carp to EDID that violate their checksums or otherwise return
> > unexpected illegal data upon reading. These are more likely to be
> > inconsistent bad connections rather than being intended.
> 
> I don't think null_edid_counter is actually used by anything.
> So apart from wondering why the mode list has turned strange
> is there some way I can still see from the logs that the
> EDID has become all zeroes?

The ones in question, it's every time we read the EDID it comes back
zero. I am betting that transient everything-is-zero rather than
spurious data is rare enough not to worry about.

An alternative would be to pass the log level to the bad_edid dumper, or
just make it debug for even gibberish edids?
-Chris