drm/amd/powerplay: Enable/Disable NBPSTATE on On/OFF of UVD

We observe black lines (underflow) on display when playing a
4K video with UVD. On Disabling Low memory P state this issue is
not seen.
Multiple runs of power measurement shows no imapct.
Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Signed-off-by: Satyajit Sahu <satyajit.sahu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/powerplay/hwmgr/smu8_hwmgr.c

@@ -1228,14 +1228,17 @@ static int smu8_dpm_force_dpm_level(struct pp_hwmgr *hwmgr,
 
 static int smu8_dpm_powerdown_uvd(struct pp_hwmgr *hwmgr)
 {
-	if (PP_CAP(PHM_PlatformCaps_UVDPowerGating))
+	if (PP_CAP(PHM_PlatformCaps_UVDPowerGating)) {
+		smu8_nbdpm_pstate_enable_disable(hwmgr, true, true);
 		return smum_send_msg_to_smc(hwmgr, PPSMC_MSG_UVDPowerOFF);
+	}
 	return 0;
 }
 
 static int smu8_dpm_powerup_uvd(struct pp_hwmgr *hwmgr)
 {
 	if (PP_CAP(PHM_PlatformCaps_UVDPowerGating)) {
+		smu8_nbdpm_pstate_enable_disable(hwmgr, false, true);
 		return smum_send_msg_to_smc_with_parameter(
 			hwmgr,
 			PPSMC_MSG_UVDPowerON,