drm/amd/amdgpu: SRIOV full reset issue with VCN

- After a full reset, VF's FB will be cleaned. This
  includes the VCN's fw_shared memory.

  However, there is no suspend-resume routine for
  SRIOV VF. Therefore, the data in the fw_shared
  memory will be lost forever and it causes engine
  hang later on.

  We must repopulate the data in fw_shared during
  SRIOV hw_init

Signed-off-by: Bokun Zhang <[email protected]>
Reviewed-by: Emily Deng <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: bokun-xxmtg

drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c

@@ -1280,6 +1280,9 @@ static int vcn_v4_0_start_sriov(struct amdgpu_device *adev)
 		if (adev->vcn.harvest_config & (1 << i))
 			continue;
 
+		// Must re/init fw_shared at beginning
+		vcn_v4_0_fw_shared_init(adev, i);
+
 		table_size = 0;
 
 		MMSCH_V4_0_INSERT_DIRECT_RD_MOD_WT(SOC15_REG_OFFSET(VCN, i,