[PATCH v2] drm/amdgpu: Fix the logic for NPS request failure

[Lijo Lazar]

On a hive, NPS request is placed by the first one for all devices in the
hive. If the request fails, mark the mode as UNKNOWN so that subsequent
devices on unload don't request it. Also, fix the mutex double lock
issue in error condition, should have been mutex_unlock.

Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
Reviewed-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>

Fixes: 44d5206ec07c ("drm/amdgpu: Place NPS mode request on unload")
---
v2: Add a debug log for debug purpose (Rajneesh)

 drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c | 28 ++++++++++++++----------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
index fcdbcff57632..3ef5066ca529 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
@@ -1586,26 +1586,30 @@ int amdgpu_xgmi_request_nps_change(struct amdgpu_device *adev,
 	 * devices don't request anymore.
 	 */
 	mutex_lock(&hive->hive_lock);
+	if (atomic_read(&hive->requested_nps_mode) ==
+	    UNKNOWN_MEMORY_PARTITION_MODE) {
+		dev_dbg(adev->dev, "Unexpected entry for hive NPS change");
+		mutex_unlock(&hive->hive_lock);
+		return 0;
+	}
 	list_for_each_entry(tmp_adev, &hive->device_list, gmc.xgmi.head) {
 		r = adev->gmc.gmc_funcs->request_mem_partition_mode(
 			tmp_adev, req_nps_mode);
 		if (r)
-			goto err;
+			break;
+	}
+	if (r) {
+		/* Request back current mode if one of the requests failed */
+		cur_nps_mode =
+			adev->gmc.gmc_funcs->query_mem_partition_mode(tmp_adev);
+		list_for_each_entry_continue_reverse(
+			tmp_adev, &hive->device_list, gmc.xgmi.head)
+			adev->gmc.gmc_funcs->request_mem_partition_mode(
+				tmp_adev, cur_nps_mode);
 	}
 	/* Set to UNKNOWN so that other devices don't request anymore */
 	atomic_set(&hive->requested_nps_mode, UNKNOWN_MEMORY_PARTITION_MODE);
-
 	mutex_unlock(&hive->hive_lock);
 
-	return 0;
-err:
-	/* Request back current mode if one of the requests failed */
-	cur_nps_mode = adev->gmc.gmc_funcs->query_mem_partition_mode(tmp_adev);
-	list_for_each_entry_continue_reverse(tmp_adev, &hive->device_list,
-					     gmc.xgmi.head)
-		adev->gmc.gmc_funcs->request_mem_partition_mode(tmp_adev,
-								cur_nps_mode);
-	mutex_lock(&hive->hive_lock);
-
 	return r;
 }
-- 
2.25.1