Flaky tests for mediatek mt8173/mt8183

[Vignesh Raman]

Hi Maintainers,

There are some flaky tests reported for mediatek mt8173 and mt8183 
display driver testing in drm-ci.

=== mediatek mt8173 ===
# Board Name: mt8173-elm-hana.dtb
# Linux Version: 6.7.0-rc3
# IGT Version: 1.28-gd2af13d9f
# Failure Rate: 50

Pipeline url:
https://gitlab.freedesktop.org/vigneshraman/linux/-/jobs/52857571
https://gitlab.freedesktop.org/vigneshraman/linux/-/jobs/52923475

Below test shows inconsistency across multiple runs, giving
results of Pass and Timeout/Fail alternately

kms_cursor_legacy at cursor-vs-flip-atomic-transitions: Timeout and also 
reported as flaky by deqp-runner:
Starting subtest: cursor-vs-flip-atomic-transitions
Using pipe A & eDP-1
Using a target of 128 cursor updates per quarter-vblank
page flip 8 was delayed, missed 6 frames
page flip 25 was delayed, missed 6 frames
page flip 1 was delayed, missed 15 frames

kms_prop_blob at invalid-set-prop (Fail):
CRITICAL: Test assertion failure function prop_tests, file ../tests 
/kms_prop_blob.c:342:
CRITICAL: Failed assertion: drmIoctl(fd, DRM_IOCTL_MODE_OBJ_SETPROPERTY, 
&set_prop) == -1 && errno == EINVAL
CRITICAL: Last errno: 13, Permission denied
igt_core-INFO: Stack trace:
igt_core-INFO:   #0 ../lib/igt_core.c:1988 __igt_fail_assert()
igt_core-INFO:   #1 ../tests/kms_prop_blob.c:312 prop_tests()
igt_core-INFO:   #2 ../tests/kms_prop_blob.c:382 
__igt_unique____real_main350()
igt_core-INFO:   #3 ../tests/kms_prop_blob.c:350 main()
igt_core-INFO:   #4 [__libc_init_first+0x80]
igt_core-INFO:   #5 [__libc_start_main+0x98]
igt_core-INFO:   #6 [_start+0x30]

kms_prop_blob at invalid-set-prop-any (Fail):
CRITICAL: Test assertion failure function prop_tests, file 
../tests/kms_prop_blob.c:334:
CRITICAL: Failed assertion: drmIoctl(fd, DRM_IOCTL_MODE_OBJ_SETPROPERTY, 
&set_prop) == -1 && errno == EINVAL
CRITICAL: Last errno: 13, Permission denied
igt_core-INFO: Stack trace:
igt_core-INFO:   #0 ../lib/igt_core.c:1988 __igt_fail_assert()
igt_core-INFO:   #1 ../tests/kms_prop_blob.c:321 prop_tests()
igt_core-INFO:   #2 ../tests/kms_prop_blob.c:382 
__igt_unique____real_main350()
igt_core-INFO:   #3 ../tests/kms_prop_blob.c:350 main()
igt_core-INFO:   #4 [__libc_init_first+0x80]
igt_core-INFO:   #5 [__libc_start_main+0x98]
igt_core-INFO:   #6 [_start+0x30]

=== mediatek mt8183 ===
# Board Name: mt8183-kukui-jacuzzi-juniper-sku16.dtb
# Linux Version: 6.7.0-rc3
# IGT Version: 1.28-gd2af13d9f
# Failure Rate: 100

Pipeline url:
https://gitlab.freedesktop.org/vigneshraman/linux/-/jobs/52925486

# Reported as flaky by deqp-runner
kms_cursor_legacy at cursor-vs-flip-atomic-transitions:

Starting subtest: cursor-vs-flip-atomic-transitions
Using pipe A & eDP-1
Using a target of 128 cursor updates per quarter-vblank
page flip 1 was delayed, missed 2 frames
page flip 2 was delayed, missed 9 frames
page flip 7 was delayed, missed 1 frames
page flip 8 was delayed, missed 2 frames

I will add these tests in 
drivers/gpu/drm/ci/xfails/mediatek-mt8173-display-flakes.txt and 
drivers/gpu/drm/ci/xfails/mediatek-mt8183-display-flakes.txt 
(https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/Documentation/gpu/automated_testing.rst#n70)

Please could you have a look at these failures and let us know if you 
need more information. Thank you.

Regards,
Vignesh