`sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t kms_writeback`

[9445.317993] [1/4] kms_writeback (writeback-pixel-formats)
[9445.623499] [2/4] kms_writeback (writeback-invalid-parameters)
[9447.076263] [3/4] kms_writeback (writeback-fb-id)
[9447.371402] [4/4] kms_writeback (writeback-check-output)
Done.



`sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_writeback`

IGT-Version: 1.25-gc36f7973 (x86_64) (Linux: 5.10.0-rc2drmsumo+ x86_64)
Starting subtest: writeback-pixel-formats
Subtest writeback-pixel-formats: SUCCESS (0.000s)
Starting subtest: writeback-invalid-parameters
Subtest writeback-invalid-parameters: SUCCESS (0.000s)
Starting subtest: writeback-fb-id
Subtest writeback-fb-id: SUCCESS (0.017s)
Starting subtest: writeback-check-output
Subtest writeback-check-output: SUCCESS (0.125s)

`sudo IGT_FORCE_DRIVER=vkms build/tests/kms_writeback`

IGT-Version: 1.25-gc36f7973 (x86_64) (Linux: 5.10.0-rc2drmsumo+ x86_64)
Starting subtest: writeback-pixel-formats
Subtest writeback-pixel-formats: SUCCESS (0.000s)
Starting subtest: writeback-invalid-parameters
Subtest writeback-invalid-parameters: SUCCESS (0.000s)
Starting subtest: writeback-fb-id
Subtest writeback-fb-id: SUCCESS (0.017s)
Starting subtest: writeback-check-output
Subtest writeback-check-output: SUCCESS (0.126s)