[PATCH 12/13] drm/amdgpu: Skip AC/DC notification while the GPU is runtime suspended

[Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>]

From: Andre Eikmeyer <dev@deq.rocks>

Plugging or unplugging the charger raises an ACPI AC event. The handler
sent the new power source to the SMU without a runtime PM reference, so
with GMUX keeping the GPU off every SMU message spun on skipped register
reads for seconds. A runtime resume racing with that left the SMU
firmware unable to start on MacBookPro15,1 and the GPU in runtime PM
error state. Record the power source only and let the resume apply it.

Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
Signed-off-by: Andre Eikmeyer <dev@deq.rocks>
---
 drivers/gpu/drm/amd/pm/amdgpu_dpm.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
index 808be6c42..b64f0b681 100644
--- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
+++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
@@ -30,6 +30,7 @@
 #include "amd_pcie.h"
 #include "amdgpu_display.h"
 #include "hwmgr.h"
+#include <linux/pm_runtime.h>
 #include <linux/power_supply.h>
 #include "amdgpu_smu.h"
 
@@ -498,20 +499,26 @@ int amdgpu_dpm_smu_i2c_bus_access(struct amdgpu_device *adev,
 
 void amdgpu_pm_acpi_event_handler(struct amdgpu_device *adev)
 {
+	int active = 0;
+
 	if (adev->pm.dpm_enabled) {
 		mutex_lock(&adev->pm.mutex);
+		active = adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX ?
+				pm_runtime_get_if_active(adev->dev) : 1;
+
 		if (power_supply_is_system_supplied() > 0)
 			adev->pm.ac_power = true;
 		else
 			adev->pm.ac_power = false;
 
-		if (adev->powerplay.pp_funcs &&
-		    adev->powerplay.pp_funcs->notify_ac_dc)
-			amdgpu_dpm_notify_ac_dc(adev);
-
-		if (is_support_sw_smu(adev))
-			smu_set_ac_dc(adev->powerplay.pp_handle, true);
+		if (active) {
+			if (adev->powerplay.pp_funcs &&
+			    adev->powerplay.pp_funcs->notify_ac_dc)
+				amdgpu_dpm_notify_ac_dc(adev);
 
+			if (is_support_sw_smu(adev))
+				smu_set_ac_dc(adev->powerplay.pp_handle, true);
+		}
 		mutex_unlock(&adev->pm.mutex);
 	}
 }
-- 
2.55.0