drm/amd/powerplay: check prerequisite for VCN power gating

VCN DPM is a necessary prerequisite for VCN power gating.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/navi10_ppt.c

@@ -574,15 +574,19 @@ static int navi10_dpm_set_uvd_enable(struct smu_context *smu, bool enable)
 	struct smu_power_gate *power_gate = &smu_power->power_gate;
 
 	if (enable && power_gate->uvd_gated) {
+		if (smu_feature_is_enabled(smu, SMU_FEATURE_DPM_UVD_BIT)) {
 			ret = smu_send_smc_msg_with_param(smu, SMU_MSG_PowerUpVcn, 1);
 			if (ret)
 				return ret;
+		}
 		power_gate->uvd_gated = false;
 	} else {
 		if (!enable && !power_gate->uvd_gated) {
+			if (smu_feature_is_enabled(smu, SMU_FEATURE_DPM_UVD_BIT)) {
 				ret = smu_send_smc_msg(smu, SMU_MSG_PowerDownVcn);
 				if (ret)
 					return ret;
+			}
 			power_gate->uvd_gated = true;
 		}
 	}