[PATCH] drm/amdgpu/smu: add an update table lock

[Alex Deucher]

The driver uses a staging buffer to update tables in the SMU.
Add a lock to make sure we don't try and do this concurrently
by accident.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/powerplay/amdgpu_smu.c     | 7 ++++++-
 drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
index 9f2428fd98f6..437a3e7b36b4 100644
--- a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
+++ b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
@@ -530,6 +530,7 @@ int smu_update_table(struct smu_context *smu, enum smu_table_id table_index, int
 
 	table_size = smu_table->tables[table_index].size;
 
+	mutex_lock(&smu->update_table_lock);
 	if (drv2smu) {
 		memcpy(table->cpu_addr, table_data, table_size);
 		/*
@@ -544,13 +545,16 @@ int smu_update_table(struct smu_context *smu, enum smu_table_id table_index, int
 					  SMU_MSG_TransferTableSmu2Dram,
 					  table_id | ((argument & 0xFFFF) << 16));
 	if (ret)
-		return ret;
+		goto unlock;
 
 	if (!drv2smu) {
 		amdgpu_asic_flush_hdp(adev, NULL);
 		memcpy(table_data, table->cpu_addr, table_size);
 	}
 
+unlock:
+	mutex_unlock(&smu->update_table_lock);
+
 	return ret;
 }
 
@@ -900,6 +904,7 @@ static int smu_sw_init(void *handle)
 
 	mutex_init(&smu->sensor_lock);
 	mutex_init(&smu->metrics_lock);
+	mutex_init(&smu->update_table_lock);
 
 	smu->watermarks_bitmap = 0;
 	smu->power_profile_mode = PP_SMC_POWER_PROFILE_BOOTUP_DEFAULT;
diff --git a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
index 97b6714e83e6..506288072e8e 100644
--- a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
+++ b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
@@ -362,6 +362,7 @@ struct smu_context
 	struct mutex			mutex;
 	struct mutex			sensor_lock;
 	struct mutex			metrics_lock;
+	struct mutex			update_table_lock;
 	uint64_t pool_size;
 
 	struct smu_table_context	smu_table;
-- 
2.24.1