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From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] drm: Silence zero EDID carping
Date: Thu, 29 Oct 2020 18:09:12 +0200	[thread overview]
Message-ID: <20201029160912.GE6112@intel.com> (raw)
In-Reply-To: <160398728309.7048.13594460258034679908@build.alporthouse.com>

On Thu, Oct 29, 2020 at 04:01:23PM +0000, Chris Wilson wrote:
> 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?

I suspect debug should be good enough for this. The user is probably
going to notice some problem with their display resolution if the
EDID is bad/zero, so we should still get the bug report.

-- 
Ville Syrjälä
Intel
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

WARNING: multiple messages have this Message-ID (diff)
From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] drm: Silence zero EDID carping
Date: Thu, 29 Oct 2020 18:09:12 +0200	[thread overview]
Message-ID: <20201029160912.GE6112@intel.com> (raw)
In-Reply-To: <160398728309.7048.13594460258034679908@build.alporthouse.com>

On Thu, Oct 29, 2020 at 04:01:23PM +0000, Chris Wilson wrote:
> 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?

I suspect debug should be good enough for this. The user is probably
going to notice some problem with their display resolution if the
EDID is bad/zero, so we should still get the bug report.

-- 
Ville Syrjälä
Intel
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2020-10-29 16:09 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-29 11:00 [Intel-gfx] [PATCH] drm: Silence zero EDID carping Chris Wilson
2020-10-29 11:00 ` Chris Wilson
2020-10-29 12:27 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork
2020-10-29 14:07 ` [Intel-gfx] [PATCH] " Ville Syrjälä
2020-10-29 14:07   ` Ville Syrjälä
2020-10-29 16:01   ` [Intel-gfx] " Chris Wilson
2020-10-29 16:01     ` Chris Wilson
2020-10-29 16:09     ` Ville Syrjälä [this message]
2020-10-29 16:09       ` Ville Syrjälä
2020-10-29 16:44 ` [igt-dev] [PATCH v2] drm: Quieten [zero] " Chris Wilson
2020-10-29 16:44   ` Chris Wilson
2020-10-29 16:59   ` [igt-dev] " Ville Syrjälä
2020-10-29 16:59     ` Ville Syrjälä
2020-10-29 16:55 ` [igt-dev] ✗ Fi.CI.BUILD: failure for " Patchwork

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