[Intel-gfx] [PATCH 0/3] drm/i915: Fix SKL+ 90/270 degree rotated scanout

[Ville Syrjälä]

On Tue, Jun 06, 2017 at 05:15:30PM +0200, Maarten Lankhorst wrote:
> Hey,
> 
> Op 06-06-17 om 10:29 schreef Tvrtko Ursulin:
> >
> > On 06/06/2017 09:06, Maarten Lankhorst wrote:
> >> Op 05-04-17 om 15:49 schreef Ville Syrjälä:
> >>> On Fri, Mar 31, 2017 at 10:23:18PM +0100, Chris Wilson wrote:
> >>>> On Fri, Mar 31, 2017 at 09:00:53PM +0300, ville.syrjala at linux.intel.com wrote:
> >>>>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >>>>>
> >>>>> I figured it's about time I fix what I broke with my fb offset stuff.
> >>>>> I've posted the scaler thing before, but the watermark and fbc stuff
> >>>>> is new.
> >>>>>
> >>>>> Based on some quick tests the WM fixes seem effective. Or at least
> >>>>> underruns seemed to disappear when I was running xonotic with 90/270
> >>>>> degree rotation.
> >>>> The key question for me is would we be able to detect any of the errors
> >>>> in igt? How can we improve our testing?
> >>> The rotation test definitely would need some love. It fails to detect
> >>> these problems because it scans out a square image. Making it non-square
> >>> would at least catch the use of the scaler when it shouldn't be used.
> >>>
> >>> Detecting the watermark breakage is less clear. I suppose making the
> >>> plane have a very wide or very tall aspect ratio might help induce
> >>> underruns with the broken wm code.
> >>>
> >>> Another thing that may or may not be missing from the test is panning.
> >>> I'd also like to test scaling, but sadly our hardware makes that
> >>> rather hard by not allowing us to force nearest and/or linear filtering,
> >>> and bspec doesn't actually document what kind of algorithm the hardware
> >>> uses for the different filter modes.
> >>>
> >> Agreed, the whole series is useful but until we have some tests we may as well not commit it. Nothing prevents it from being broken again in the next commit. :(
> >
> > In case tests hit a stumbling blocks/delays, I would appreciate if this got reviewed and merged soonish. As it stands I've been applying (and occasionally forgetting to apply) patches locally since September.
> >
> > And FWIW I would report if it got re-broken, since I'm using monitors in portrait, and like to run recent drm-tip to help catch issues missed elsewhere.
> >
> >> I'll take a look and see if I can make kms_rotation_crc break without this test.
> >
> > Would also need to upgrade the test to basic, or count on extended runs getting attention soon? 
> Maybe?
> 
> I've pushed the fixed test. Managed to test that the scaler is enabled incorrectly and the WM underruns.
> 
> Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

Thanks for the review, and updating the tests.

Series pushed to dinq.

-- 
Ville Syrjälä
Intel OTC