drm/radeon/kms/pm: track current voltage (v2)

track the current voltage level and avoid setting it
if the requested voltage is already set.

v2: check voltage type before checking current voltage
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/evergreen.c

@@ -45,8 +45,12 @@ void evergreen_pm_misc(struct radeon_device *rdev)
 	struct radeon_power_state *ps = &rdev->pm.power_state[requested_index];
 	struct radeon_voltage *voltage = &ps->clock_info[0].voltage;
 
-	if ((voltage->type == VOLTAGE_SW) && voltage->voltage)
-		radeon_atom_set_voltage(rdev, voltage->voltage);
+	if ((voltage->type == VOLTAGE_SW) && voltage->voltage) {
+		if (voltage->voltage != rdev->pm.current_vddc) {
+			radeon_atom_set_voltage(rdev, voltage->voltage);
+			rdev->pm.current_vddc = voltage->voltage;
+		}
+	}
 }
 
 void evergreen_pm_prepare(struct radeon_device *rdev)

drivers/gpu/drm/radeon/r600.c

@@ -561,9 +561,12 @@ void r600_pm_misc(struct radeon_device *rdev)
 	struct radeon_power_state *ps = &rdev->pm.power_state[requested_index];
 	struct radeon_voltage *voltage = &ps->clock_info[0].voltage;
 
-	if ((voltage->type == VOLTAGE_SW) && voltage->voltage)
-		radeon_atom_set_voltage(rdev, voltage->voltage);
-
+	if ((voltage->type == VOLTAGE_SW) && voltage->voltage) {
+		if (voltage->voltage != rdev->pm.current_vddc) {
+			radeon_atom_set_voltage(rdev, voltage->voltage);
+			rdev->pm.current_vddc = voltage->voltage;
+		}
+	}
 }
 
 bool r600_gui_idle(struct radeon_device *rdev)

drivers/gpu/drm/radeon/radeon.h

@@ -748,6 +748,7 @@ struct radeon_pm {
 	int                     default_power_state_index;
 	u32                     current_sclk;
 	u32                     current_mclk;
+	u32                     current_vddc;
 	struct radeon_i2c_chan *i2c_bus;
 	/* selected pm method */
 	enum radeon_pm_method     pm_method;

drivers/gpu/drm/radeon/radeon_atombios.c

@@ -1966,6 +1966,7 @@ void radeon_atombios_get_power_modes(struct radeon_device *rdev)
 
 	rdev->pm.current_power_state_index = rdev->pm.default_power_state_index;
 	rdev->pm.current_clock_mode_index = 0;
+	rdev->pm.current_vddc = rdev->pm.power_state[rdev->pm.default_power_state_index].clock_info[0].voltage.voltage;
 }
 
 void radeon_atom_set_clock_gating(struct radeon_device *rdev, int enable)

drivers/gpu/drm/radeon/radeon_pm.c

@@ -387,6 +387,7 @@ void radeon_pm_resume(struct radeon_device *rdev)
 	rdev->pm.current_clock_mode_index = 0;
 	rdev->pm.current_sclk = rdev->clock.default_sclk;
 	rdev->pm.current_mclk = rdev->clock.default_mclk;
+	rdev->pm.current_vddc = rdev->pm.power_state[rdev->pm.default_power_state_index].clock_info[0].voltage.voltage;
 	mutex_unlock(&rdev->pm.mutex);
 	radeon_pm_compute_clocks(rdev);
 }

drivers/gpu/drm/radeon/rv770.c

@@ -48,8 +48,13 @@ void rv770_pm_misc(struct radeon_device *rdev)
 	struct radeon_power_state *ps = &rdev->pm.power_state[requested_index];
 	struct radeon_voltage *voltage = &ps->clock_info[0].voltage;
 
-	if ((voltage->type == VOLTAGE_SW) && voltage->voltage)
-		radeon_atom_set_voltage(rdev, voltage->voltage);
+
+	if ((voltage->type == VOLTAGE_SW) && voltage->voltage) {
+		if (voltage->voltage != rdev->pm.current_vddc) {
+			radeon_atom_set_voltage(rdev, voltage->voltage);
+			rdev->pm.current_vddc = voltage->voltage;
+		}
+	}
 }
 
 /*