Re: ✗ Xe.CI.Full: failure for AuxCCS handling and render compression modifiers

[Tvrtko Ursulin <tvrtko.ursulin@igalia.com>]

+ Rodrigo and Jani for possible CI/display insights or adding correct Cc 
please.

On 31/01/2025 20:26, Patchwork wrote:
> igt@kms_flip_tiling@flip-change-tiling@pipe-a-hdmi-a-1-y-rc-ccs-cc-to-y-mc-ccs (NEW):
> 
>   * shard-adlp: NOTRUN -> FAIL
>     <https://intel-gfx-ci.01.org/tree/intel-xe/xe-pw-144186v1/shard-adlp-2/igt@kms_flip_tiling@flip-change-tiling@pipe-a-hdmi-a-1-y-rc-ccs-cc-to-y-mc-ccs.html> +66 other tests fail

Two things here.

First it seems to be some sort of a race condition in crc collection 
and/or vblank counter handling. Tests work individually but fail one run 
in sequence. Bad CRC also varies run to run, while visually things look 
fine to me on screen. Also a delay before collecting the crc seems to 
improve things.

I instrumented things a bit but I don't really understand it. For 
example collecting the reference CRC appears to have some "collect it at 
the next vblank logic", but I am not sure that works correctly. Ie.

Working case:
==========================================

Getting the reference CRC:
------------------------------------------
(kms_flip_tiling:14174) igt_pipe_crc-DEBUG: crc for vblank 703868, 
target 703869; crc[0]=b82b36e4
(kms_flip_tiling:14174) igt_pipe_crc-DEBUG: crc for vblank 703869, 
target 703869; crc[0]=b82b36e4

reference_crc[0]=b82b36e4

Compare after flip:

(kms_flip_tiling:14174) igt_pipe_crc-DEBUG: crc for vblank 703870, 
target 703872; crc[0]=b82b36e4
(kms_flip_tiling:14174) igt_pipe_crc-DEBUG: crc for vblank 703871, 
target 703872; crc[0]=2aa66f1d
(kms_flip_tiling:14174) igt_pipe_crc-DEBUG: crc for vblank 703872, 
target 703872; crc[0]=b82b36e4

reference_crc[0]=b82b36e4 crc[0]=b82b36e4


Failing case:
==========================================

Getting the reference CRC:
------------------------------------------
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698273, 
target 698278; crc[0]=b82b36e4
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698274, 
target 698278; crc[0]=b82b36e4
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698275, 
target 698278; crc[0]=b82b36e4
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698276, 
target 698278; crc[0]=b82b36e4
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698277, 
target 698278; crc[0]=b82b36e4
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698278, 
target 698278; crc[0]=7b978b62

reference_crc[0]=7b978b62

Compare after flip:
------------------------------------------
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698279, 
target 698281; crc[0]=dbec96bd
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698280, 
target 698281; crc[0]=da444d0a
(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: crc for vblank 698281, 
target 698281; crc[0]=b82b36e4

reference_crc[0]=7b978b62 crc[0]=b82b36e4

(kms_flip_tiling:14145) igt_pipe_crc-DEBUG: CRC mismatch at index 0: 
0x7b978b62 != 0xb82b36e4

Second thing - how come xe shards have ADL-P when xe does not support 
it, while i915 shards don't, when it does? :))

Regards,

Tvrtko