drm/amdgpu: Enable/disable gfx PG feature in rlc safe mode

This is required by gfx hw and can fix the rlc hang when
do s3 stree test on Cz/St.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Hang Zhou <hang.zhou@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c

@@ -5660,6 +5660,11 @@ static int gfx_v8_0_set_powergating_state(void *handle,
 	if (amdgpu_sriov_vf(adev))
 		return 0;
 
+	if (adev->pg_flags & (AMD_PG_SUPPORT_GFX_SMG |
+				AMD_PG_SUPPORT_RLC_SMU_HS |
+				AMD_PG_SUPPORT_CP |
+				AMD_PG_SUPPORT_GFX_DMG))
+		adev->gfx.rlc.funcs->enter_safe_mode(adev);
 	switch (adev->asic_type) {
 	case CHIP_CARRIZO:
 	case CHIP_STONEY:
@@ -5709,7 +5714,11 @@ static int gfx_v8_0_set_powergating_state(void *handle,
 	default:
 		break;
 	}
-
+	if (adev->pg_flags & (AMD_PG_SUPPORT_GFX_SMG |
+				AMD_PG_SUPPORT_RLC_SMU_HS |
+				AMD_PG_SUPPORT_CP |
+				AMD_PG_SUPPORT_GFX_DMG))
+		adev->gfx.rlc.funcs->exit_safe_mode(adev);
 	return 0;
 }