Fix race condition issue when multiple vcn starts are called.

Signed-off-by: James Zhu <James.Zhu@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 4 ++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
index f96464e..aa7663f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
@@ -63,6 +63,7 @@ int amdgpu_vcn_sw_init(struct amdgpu_device *adev)
         int i, r;
 
         INIT_DELAYED_WORK(&adev->vcn.idle_work, amdgpu_vcn_idle_work_handler);
+       mutex_init(&adev->vcn.vcn_pg_lock);
 
         switch (adev->asic_type) {
         case CHIP_RAVEN:
@@ -210,6 +211,7 @@ int amdgpu_vcn_sw_fini(struct amdgpu_device *adev)
         }
 
         release_firmware(adev->vcn.fw);
+       mutex_destroy(&adev->vcn.vcn_pg_lock);
 
         return 0;
 }
@@ -321,6 +323,7 @@ void amdgpu_vcn_ring_begin_use(struct amdgpu_ring *ring)
         struct amdgpu_device *adev = ring->adev;
         bool set_clocks = !cancel_delayed_work_sync(&adev->vcn.idle_work);
 
+       mutex_lock(&adev->vcn.vcn_pg_lock);
         if (set_clocks) {
                 amdgpu_gfx_off_ctrl(adev, false);
                 amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_VCN,
@@ -345,6 +348,7 @@ void amdgpu_vcn_ring_begin_use(struct amdgpu_ring *ring)
 
                 adev->vcn.pause_dpg_mode(adev, ring->me, &new_state);
         }
+       mutex_unlock(&adev->vcn.vcn_pg_lock);
 }
 
 void amdgpu_vcn_ring_end_use(struct amdgpu_ring *ring)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
index 6fe0573..2ae110d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
@@ -200,6 +200,7 @@ struct amdgpu_vcn {
         struct drm_gpu_scheduler *vcn_dec_sched[AMDGPU_MAX_VCN_INSTANCES];
         uint32_t                 num_vcn_enc_sched;
         uint32_t                 num_vcn_dec_sched;
+       struct mutex             vcn_pg_lock;
 
         unsigned        harvest_config;
         int (*pause_dpg_mode)(struct amdgpu_device *adev,
--
2.7.4