[PATCH 5.4 074/191] drm/amdgpu/smu: add metrics table lock for navi (v2)

[Greg Kroah-Hartman]

From: Alex Deucher <alexander.deucher@xxxxxxx>

commit e0e384c398d4638e54b6d2098f0ceaafdab870ee upstream.

To protect access to the metrics table.

v2: unlock on error

Bug: https://gitlab.freedesktop.org/drm/amd/issues/900
Reviewed-by: Kevin Wang <kevin1.wang@xxxxxxx>
Reviewed-by: Evan Quan <evan.quan@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/amd/powerplay/navi10_ppt.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
+++ b/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
@@ -547,17 +547,20 @@ static int navi10_get_metrics_table(stru
 	struct smu_table_context *smu_table= &smu->smu_table;
 	int ret = 0;
 
+	mutex_lock(&smu->metrics_lock);
 	if (!smu_table->metrics_time || time_after(jiffies, smu_table->metrics_time + msecs_to_jiffies(100))) {
 		ret = smu_update_table(smu, SMU_TABLE_SMU_METRICS, 0,
 				(void *)smu_table->metrics_table, false);
 		if (ret) {
 			pr_info("Failed to export SMU metrics table!\n");
+			mutex_unlock(&smu->metrics_lock);
 			return ret;
 		}
 		smu_table->metrics_time = jiffies;
 	}
 
 	memcpy(metrics_table, smu_table->metrics_table, sizeof(SmuMetrics_t));
+	mutex_unlock(&smu->metrics_lock);
 
 	return ret;
 }