Re: [PATCH 3/3] drm/i915/gen9: Drop invalid WARN() during data rate calculation

Matt Roper
2016-06-17T21:25:12Z

On Mon, Jun 13, 2016 at 11:33:50AM +0200, Maarten Lankhorst wrote:
> Op 10-06-16 om 00:14 schreef Matt Roper:
> > It's possible to have a non-zero plane mask and still wind up with a
> > total data rate of zero. There are two cases where this can happen:
> >
> > * planes are active (from the KMS point of view), but are
> > all fully clipped (positioned offscreen)
> > * the only active plane on a CRTC is the cursor (which is handled
> > independently and not counted into the general data rate computations
> >
> > These are both valid display setups (although unusual), so we need to
> > drop the WARN().
> Is there a testcase that triggers this warn? Something for
> kms_universal_planes perhaps?

I do have the start of a new IGT testcase that generates hundreds of
random display configurations (for the purposes of searching for
watermark corner cases); that test triggers this WARN(), but I haven't
posted it yet.

But having extra subtests in the universal plane test sounds good too;
thanks!

Matt

>
> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Testcase: kms_universal_planes.cursor-only-pipe-* (will reply here as a patch)

--
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795