[PATCH] drm/amdgpu/jpeg: fix race condition issue for jpeg start

[James Zhu]

Fix race condition issue when multiple jpeg starts are called.

Signed-off-by: James Zhu <James.Zhu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c | 16 ++++++++++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.h |  2 ++
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
index d31d65e..8996cb4e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
@@ -37,6 +37,8 @@ static void amdgpu_jpeg_idle_work_handler(struct work_struct *work);
 int amdgpu_jpeg_sw_init(struct amdgpu_device *adev)
 {
 	INIT_DELAYED_WORK(&adev->jpeg.idle_work, amdgpu_jpeg_idle_work_handler);
+	mutex_init(&adev->jpeg.jpeg_pg_lock);
+	atomic_set(&adev->jpeg.total_submission_cnt, 0);
 
 	return 0;
 }
@@ -54,6 +56,8 @@ int amdgpu_jpeg_sw_fini(struct amdgpu_device *adev)
 		amdgpu_ring_fini(&adev->jpeg.inst[i].ring_dec);
 	}
 
+	mutex_destroy(&adev->jpeg.jpeg_pg_lock);
+
 	return 0;
 }
 
@@ -83,7 +87,7 @@ static void amdgpu_jpeg_idle_work_handler(struct work_struct *work)
 		fences += amdgpu_fence_count_emitted(&adev->jpeg.inst[i].ring_dec);
 	}
 
-	if (fences == 0)
+	if (!fences && !atomic_read(&adev->jpeg.total_submission_cnt))
 		amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_JPEG,
 						       AMD_PG_STATE_GATE);
 	else
@@ -93,15 +97,19 @@ static void amdgpu_jpeg_idle_work_handler(struct work_struct *work)
 void amdgpu_jpeg_ring_begin_use(struct amdgpu_ring *ring)
 {
 	struct amdgpu_device *adev = ring->adev;
-	bool set_clocks = !cancel_delayed_work_sync(&adev->jpeg.idle_work);
 
-	if (set_clocks)
-		amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_JPEG,
+	atomic_inc(&adev->jpeg.total_submission_cnt);
+	cancel_delayed_work_sync(&adev->jpeg.idle_work);
+
+	mutex_lock(&adev->jpeg.jpeg_pg_lock);
+	amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_JPEG,
 						       AMD_PG_STATE_UNGATE);
+	mutex_unlock(&adev->jpeg.jpeg_pg_lock);
 }
 
 void amdgpu_jpeg_ring_end_use(struct amdgpu_ring *ring)
 {
+	atomic_dec(&ring->adev->jpeg.total_submission_cnt);
 	schedule_delayed_work(&ring->adev->jpeg.idle_work, JPEG_IDLE_TIMEOUT);
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.h
index 5131a0a..55fbff2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.h
@@ -46,6 +46,8 @@ struct amdgpu_jpeg {
 	unsigned harvest_config;
 	struct delayed_work idle_work;
 	enum amd_powergating_state cur_state;
+	struct mutex jpeg_pg_lock;
+	atomic_t total_submission_cnt;
 };
 
 int amdgpu_jpeg_sw_init(struct amdgpu_device *adev);
-- 
2.7.4