Comment 0 for bug 2024774

[ Impact ]

 When using kernel 6.2 or later AMD has enabled PSR selective update (PSR-SU).
 After a non-deterministic amount of time the system may hang with a message like this in the logs:
 "[amdgpu 0000:67:00.0: [drm] *ERROR* [CONNECTOR:78:eDP-1] commit wait timed out]"

 Affects users of laptops that contain:
 * AMD Rembrandt (Yellow Carp) or AMD Phoenix (Pink Sardine) chips
 * eDP panels with Parade TCONs (8-03 and 8-01 both reported to fail)

[ Test Plan ]

 * Test an affected laptop with the newer firmware and ensure that PSR-SU function can be enabled and system is stable.
 * Ensure other functions such as hotplugging monitors and suspending continue to work.

[ Where problems could occur ]

 * Affected firmware only is loaded on Rembrandt and Phoenix laptops. Problems would be localized to these machines.

[ Other Info ]
The minimum firmware needed to help these hangs:
* Rembrandt: 0x400003a or later
* Phoenix: 0x8001000 or later

The following commit upgrades the firmware for Rembrandt (amdgpu/yellow_carp_dmcub.bin) to 0x400003c:
9dbd8ec2 ("amdgpu: DMCUB updates for various AMDGPU asics")

The following commit upgrades the firmware for Phoenix (amdgpu/dcn_3_1_4_dmcub.bin) to 0x8001a00:
045b2136 ("amdgpu: update DMCUB to v0.0.172.0 for various AMDGPU ASICs")