Re: [PATCH] drm/i915/skl: Support Y tiling in MMIO flips

Daniel Vetter
2015-04-20T17:44:21Z

On Mon, Apr 20, 2015 at 05:38:20PM +0100, Tvrtko Ursulin wrote:
>
> On 04/20/2015 05:22 PM, Daniel Vetter wrote:
> >On Mon, Apr 20, 2015 at 04:22:48PM +0100, Tvrtko Ursulin wrote:
> >>From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >>
> >>Add Y tiling support to skl_do_mmio_flip.
> >>
> >>Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >>Cc: Damien Lespiau <damien.lespiau@intel.com>
> >>Cc: Sonika Jindal <sonika.jindal@intel.com>
> >>Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> >>---
> >>Looks like we completely missed this completely parallel instance of plane
> >>programming code when working on Y tiling support!
> >>
> >>Will rotation need supporting here as well?
> >
> >Oh dear this is a bit ugly. We definitely need either this for 4.1 or take
> >out the Y-tiling support for 4.1. Rotation only made 4.2, so I think
> >we're good, but we do indeed need to take rotation into account here too.
>
> What is ugly, this patch or the overall situation?
>
> >And it seems like we also need a pile of igt testcases to make sure
> >Y-tiling, rotation (even 180 probably) works correctly with pageflips. Yay
> >for kms_flip growing even more.
>
> I added Y to kms_flip_tiling back then - but both that one and kms_flip
> don't do any pipe crc. So not much use in automated fashion. And testdisplay
> apparently does not hit this path.
>
> I did not have working crc hw back then, maybe that has changed, I'll check
> it and then, depending on the outcome, see if I can add something automated.
>
> Either way, adding this fix sounds better than reverting everything.

On 2nd thought skl is still tagged as preliminary, so we don't have any
issues here at all. Queued for -next, thanks for the patch.

While looking at skl_do_mmio_flip I noticed though that rotation support
seems to be completely absent. Or did I miss something?
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation