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

Tvrtko Ursulin
2015-04-20T16:38:23Z

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.

Regards,

Tvrtko