drm/amd/powerplay: refine the logic of whether need to update power state.

BugLink: http://bugs.launchpad.net/bugs/1546572

Better handle power state changes.
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
(cherry picked from commit f4caf3e5)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpu/drm/amd/powerplay/eventmgr/psm.c

@@ -86,9 +86,10 @@ int psm_set_performance_states(struct pp_eventmgr *eventmgr, unsigned long *stat
 int psm_adjust_power_state_dynamic(struct pp_eventmgr *eventmgr, bool skip)
 {
 
-	const struct pp_power_state  *pcurrent;
-	struct pp_power_state  *requested;
+	struct pp_power_state *pcurrent;
+	struct pp_power_state *requested;
 	struct pp_hwmgr *hwmgr;
+	bool equal;
 
 	if (skip)
 		return 0;
@@ -97,7 +98,13 @@ int psm_adjust_power_state_dynamic(struct pp_eventmgr *eventmgr, bool skip)
 	pcurrent = hwmgr->current_ps;
 	requested = hwmgr->request_ps;
 
-	if ((pcurrent != NULL || requested != NULL) && (pcurrent != requested)) {
+	if (requested == NULL)
+		return 0;
+
+	if (pcurrent == NULL || (0 != phm_check_states_equal(hwmgr, &pcurrent->hardware, &requested->hardware, &equal)))
+		equal = false;
+
+	if (!equal || phm_check_smc_update_required_for_display_configuration(hwmgr)) {
 		phm_apply_state_adjust_rules(hwmgr, requested, pcurrent);
 		phm_set_power_state(hwmgr, &pcurrent->hardware, &requested->hardware);
 		hwmgr->current_ps = requested;

drivers/gpu/drm/amd/powerplay/eventmgr/psm.h

@@ -25,6 +25,7 @@
 #include "eventmanagement.h"
 #include "eventmanager.h"
 #include "power_state.h"
+#include "hardwaremanager.h"
 
 int psm_get_ui_state(struct pp_eventmgr *eventmgr, enum PP_StateUILabel ui_label, unsigned long *state_id);