igt@kms_content_protection@ subtests - incomplete - Received signal SIGABRT.

https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_13345/re-mtlp-9/igt@kms_content_protection@legacy.html

Err	
Starting subtest: legacy
(kms_content_protection:1791) igt_kms-CRITICAL: Test assertion failure function igt_primary_plane_commit_legacy, file ../../../usr/src/igt-gpu-tools/lib/igt_kms.c:3572:
(kms_content_protection:1791) igt_kms-CRITICAL: Failed assertion: ret == 0
(kms_content_protection:1791) igt_kms-CRITICAL: Last errno: 22, Invalid argument
(kms_content_protection:1791) igt_kms-CRITICAL: error: -22 != 0
Received signal SIGABRT.
Stack trace: 
 #0 [fatal_sig_handler+0x10f]
 #1 [killpg+0x40]
 #2 [gsignal+0xcb]
 #3 [abort+0x12b]
 #4 [<unknown>+0x12b]
 #5 [__assert_fail+0x46]
 #6 [igt_fail+0x125]
 #7 [__igt_fail_assert+0x128]
 #8 [do_display_commit+0x712]
 #9 [igt_display_commit2+0x12]
 #10 [test_content_protection+0x240]
 #11 [__igt_unique____real_main832+0x3f9]
 #12 [main+0x2d]
 #13 [__libc_start_main+0xf3]
 #14 [_start+0x2e]