drm/amd/display: Reset DMCUB before HW init

[Why]
If the firmware wasn't reset by PSP or HW and is currently running
then the firmware will hang or perform underfined behavior when we
modify its firmware state underneath it.

[How]
Reset DMCUB before setting up cache windows and performing HW init.

Reviewed-by: Aurabindo Jayamohanan Pillai <Aurabindo.Pillai@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 122dae1a1813b3eed2517d590bc19ea95fe77346..e727f1dd2a9a7ca8840d4c427e31aab299c244bd 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1051,6 +1051,11 @@ static int dm_dmub_hw_init(struct amdgpu_device *adev)
                return 0;
        }
 
+       /* Reset DMCUB if it was previously running - before we overwrite its memory. */
+       status = dmub_srv_hw_reset(dmub_srv);
+       if (status != DMUB_STATUS_OK)
+               DRM_WARN("Error resetting DMUB HW: %d\n", status);
+
        hdr = (const struct dmcub_firmware_header_v1_0 *)dmub_fw->data;
 
        fw_inst_const = dmub_fw->data +