drm/amd/powerplay: fix null pointer dereference around dpm state relates

DPM state relates are not supported on the new SW SMU ASICs. But still
it's not OK to trigger null pointer dereference on accessing them.

Signed-off-by: Evan Quan <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

1 files changed, 13 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
index 03ca8c69114f..8c90baca07b2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
@@ -159,12 +159,16 @@ static ssize_t amdgpu_get_dpm_state(struct device *dev,
 	struct amdgpu_device *adev = ddev->dev_private;
 	enum amd_pm_state_type pm;
 
-	if (is_support_sw_smu(adev) && adev->smu.ppt_funcs->get_current_power_state)
-		pm = amdgpu_smu_get_current_power_state(adev);
-	else if (adev->powerplay.pp_funcs->get_current_power_state)
+	if (is_support_sw_smu(adev)) {
+		if (adev->smu.ppt_funcs->get_current_power_state)
+			pm = amdgpu_smu_get_current_power_state(adev);
+		else
+			pm = adev->pm.dpm.user_state;
+	} else if (adev->powerplay.pp_funcs->get_current_power_state) {
 		pm = amdgpu_dpm_get_current_power_state(adev);
-	else
+	} else {
 		pm = adev->pm.dpm.user_state;
+	}
 
 	return snprintf(buf, PAGE_SIZE, "%s\n",
 			(pm == POWER_STATE_TYPE_BATTERY) ? "battery" :
@@ -191,7 +195,11 @@ static ssize_t amdgpu_set_dpm_state(struct device *dev,
 		goto fail;
 	}
 
-	if (adev->powerplay.pp_funcs->dispatch_tasks) {
+	if (is_support_sw_smu(adev)) {
+		mutex_lock(&adev->pm.mutex);
+		adev->pm.dpm.user_state = state;
+		mutex_unlock(&adev->pm.mutex);
+	} else if (adev->powerplay.pp_funcs->dispatch_tasks) {
 		amdgpu_dpm_dispatch_task(adev, AMD_PP_TASK_ENABLE_USER_STATE, &state);
 	} else {
 		mutex_lock(&adev->pm.mutex);