drm/amd/display: fix system hang when PSR exits
[why] When DC driver send PSR exit dmub command to DMUB FW, it might not wait until PSR exit. Then it may hit the following deadlock situation. 1. DC driver send HW LOCK command to DMUB FW due to frame update 2. DMUB FW Set the HW lock 3. DMUB execute PSR exit sequence and stuck at polling DPG Pending register due to the HW Lock is set 4. DC driver ask DMUB FW to unlock HW lock, but DMUB FW is polling DPG pending register [how] The reason why DC driver doesn't wait until PSR exit is because some of the PSR state machine state is not update the dc driver. So when DC driver read back the PSR state, it take the state for PSR inactive. Signed-off-by: David Zhang <dingchen.zhang@amd.com> Acked-by: Leo Li <sunpeng.li@amd.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Showing
Please register or sign in to comment