RE: [PATCH] drm/displayid: reduce DisplayID checksum error logging to debug

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 23 Feb 2026, "Srinivas, Vidya" <vidya.srinivas@intel.com> wrote:
>> -----Original Message-----
>> From: Nikula, Jani <jani.nikula@intel.com>
>> Sent: 23 February 2026 16:02
>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-gfx@lists.freedesktop.org
>> Cc: intel-xe@lists.freedesktop.org; Srinivas, Vidya <vidya.srinivas@intel.com>
>> Subject: Re: [PATCH] drm/displayid: reduce DisplayID checksum error logging
>> to debug
>> 
>> On Tue, 17 Feb 2026, Vidya Srinivas <vidya.srinivas@intel.com> wrote:
>> > The patch "drm/displayid: add quirk to ignore DisplayID checksum
>> > errors" introduced a mechanism to bypass checksum validation for
>> > certain panels. However, even when ignoring the error, the code
>> > continues to log a DRM_NOTE.
>> 
>> Please refer to commits with the usual format (see git log).
>> 
>> > On affected hardware, this results in persistent "DisplayID checksum
>> > invalid" messages in the system log. This noise often misleads users
>> > into thinking there is a critical hardware failure or a functional
>> > regression, despite the quirk successfully handling the issue.
>> >
>> > Downgrade the log level from DRM_NOTE to DRM_DEBUG_KMS. This keeps
>> the
>> > diagnostic information available for kernel developers while silencing
>> > the unnecessary warning for end-users.
>> >
>> > Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
>> > ---
>> >  drivers/gpu/drm/drm_displayid.c | 2 +-
>> >  1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/drm_displayid.c
>> > b/drivers/gpu/drm/drm_displayid.c index 58d0bb6d2676..1f6d78fe29f2
>> > 100644
>> > --- a/drivers/gpu/drm/drm_displayid.c
>> > +++ b/drivers/gpu/drm/drm_displayid.c
>> > @@ -69,7 +69,7 @@ validate_displayid(const u8 *displayid, int length, int
>> idx, bool ignore_checksu
>> >  	for (i = 0; i < dispid_length; i++)
>> >  		csum += displayid[idx + i];
>> >  	if (csum) {
>> > -		DRM_NOTE("DisplayID checksum invalid, remainder is
>> %d%s\n", csum,
>> > +		DRM_DEBUG_KMS("DisplayID checksum invalid, remainder is
>> %d%s\n",
>> > +csum,
>> >  			 ignore_checksum ? " (ignoring)" : "");
>> 
>> I understand the desire to make it debug level with the quirk, but IMO it
>> needs to be more than debug level when there is no quirk.
>> 
>> BR,
>> Jani.
>> 
>
> Hello Jani
>
> Thank you so much. I understand your point.
> Only problem is other components not familiar with drm get confused about
> the message and say it is display issue. They also report this flooding
> is causing delay for their driver load etc.

It absolutely *is* a display issue, it's got a buggy EDID. It's not a
driver issue. If we go quiet about it, people will only notice the issue
through missing advanced display features as the DisplayID got skipped.

Like I said, make it debug level for displays that have the quirk
(ignore_checksum), and keep it noisier for displays that don't. If we
hit that, there's a (small) chance we can give the display vendor
feedback and have it fixed, otherwise we can add the quirk.

But the displays will never get fixed if we always keep quietly
accepting buggy EDIDs.


BR,
Jani.

>
> Regards
> Vidya
>
>> 
>> >
>> >  		if (!ignore_checksum)
>> 
>> --
>> Jani Nikula, Intel

-- 
Jani Nikula, Intel