[Intel-gfx] [PATCH] drm/i915/gen9: fix DDB partitioning for multi-screen cases

[Maarten Lankhorst]

Op 04-10-16 om 19:44 schreef Paulo Zanoni:
> Em Ter, 2016-10-04 às 14:37 -0300, Paulo Zanoni escreveu:
>> With the previous code we were only recomputing the DDB partitioning
>> for the CRTCs included in the atomic commit, so any other active
>> CRTCs
>> would end up having their DDB registers zeroed. In this patch we make
>> sure that the computed state starts as a copy of the current
>> partitioning, and then we only zero the DDBs that we're actually
>> going to recompute.
>>
>> How to reproduce the bug:
>>   1 - Enable the primary plane on pipe A
>>   2 - Enable the primary plane on pipe B
>>   3 - Enable the sprite plane on pipe A
> Forgot to mention: sprite or cursor.
Testcase: kms_cursor_legacy.cursorA-vs-flipB-atomic-transitions

Fails with:
(kms_cursor_legacy:1962) igt-kms-CRITICAL: Last errno: 22, Invalid argument
(kms_cursor_legacy:1962) igt-kms-CRITICAL: error: -22 != 0

The test succeeds with this patch applied, but it still has FIFO underruns. Oh well it's progress..