drm/amd/display: Control power gating by driver.

[Why]
This disablement would be specific for Nav10 and shouldn’t be propagated to the other programs.

[How]
Power gating is controlled by driver.
Signed-off-by: JinZe.Xu <JinZe.Xu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn302/dcn302_hwseq.c

@@ -86,17 +86,12 @@ void dcn302_dpp_pg_control(struct dce_hwseq *hws, unsigned int dpp_inst, bool po
 				1, 1000);
 		break;
 	case 4: /* DPP4 */
-		/*
-		 * Do not power gate DPP4, should be left at HW default, power on permanently.
-		 * PG on Pipe4 is De-featured, attempting to put it to PG state may result in hard
-		 * reset.
-		 * REG_UPDATE(DOMAIN9_PG_CONFIG,
-		 *		DOMAIN9_POWER_GATE, power_gate);
-		 *
-		 * REG_WAIT(DOMAIN9_PG_STATUS,
-		 *		DOMAIN9_PGFSM_PWR_STATUS, pwr_status,
-		 *		1, 1000);
-		 */
+		REG_UPDATE(DOMAIN9_PG_CONFIG,
+				DOMAIN9_POWER_GATE, power_gate);
+
+		REG_WAIT(DOMAIN9_PG_STATUS,
+				DOMAIN9_PGFSM_PWR_STATUS, pwr_status,
+				1, 1000);
 		break;
 	default:
 		BREAK_TO_DEBUGGER();
@@ -148,17 +143,12 @@ void dcn302_hubp_pg_control(struct dce_hwseq *hws, unsigned int hubp_inst, bool
 				1, 1000);
 		break;
 	case 4: /* DCHUBP4 */
-		/*
-		 * Do not power gate DCHUB4, should be left at HW default, power on permanently.
-		 * PG on Pipe4 is De-featured, attempting to put it to PG state may result in hard
-		 * reset.
-		 * REG_UPDATE(DOMAIN8_PG_CONFIG,
-		 *		DOMAIN8_POWER_GATE, power_gate);
-		 *
-		 * REG_WAIT(DOMAIN8_PG_STATUS,
-		 *		DOMAIN8_PGFSM_PWR_STATUS, pwr_status,
-		 *		1, 1000);
-		 */
+		REG_UPDATE(DOMAIN8_PG_CONFIG,
+				DOMAIN8_POWER_GATE, power_gate);
+
+		REG_WAIT(DOMAIN8_PG_STATUS,
+				DOMAIN8_PGFSM_PWR_STATUS, pwr_status,
+				1, 1000);
 		break;
 	default:
 		BREAK_TO_DEBUGGER();