drm/amd/pm: Add warning for unexpected PG requests

v1: Ideally power gate/ungate requests shouldn't come when smu block is
uninitialized. Add a WARN message to check the origins if such a thing
ever happens.

v2: Use dev_WARN to log device info (Felix/Guchun).
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Kevin Yang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c

@@ -277,8 +277,12 @@ static int smu_dpm_set_power_gate(void *handle,
 	struct smu_context *smu = handle;
 	int ret = 0;
 
-	if (!smu->pm_enabled || !smu->adev->pm.dpm_enabled)
+	if (!smu->pm_enabled || !smu->adev->pm.dpm_enabled) {
+		dev_WARN(smu->adev->dev,
+			 "SMU uninitialized but power %s requested for %u!\n",
+			 gate ? "gate" : "ungate", block_type);
 		return -EOPNOTSUPP;
+	}
 
 	switch (block_type) {
 	/*