Commit bd718638 authored by James Zhu's avatar James Zhu Committed by Alex Deucher
Browse files

drm/amdgpu/vcn: fix race condition issue for vcn start 



Fix race condition issue when multiple vcn starts are called.

v2: Removed checking the return value of cancel_delayed_work_sync()
to prevent possible races here.

v3: Add total_submission_cnt to avoid gate power unexpectedly.

v4: Remove extra counter check, and reduce counter before idle
work schedule

Signed-off-by: default avatarJames Zhu <James.Zhu@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 17e137f2

drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c

+14 −7
Original line number Diff line number Diff line
@@ -63,6 +63,8 @@ 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);

	atomic_set(&adev->vcn.total_submission_cnt, 0);



	switch (adev->asic_type) {

	case CHIP_RAVEN:
@@ -210,6 +212,7 @@ int amdgpu_vcn_sw_fini(struct amdgpu_device *adev) 
	}



	release_firmware(adev->vcn.fw);

	mutex_destroy(&adev->vcn.vcn_pg_lock);



	return 0;

}
@@ -307,7 +310,7 @@ static void amdgpu_vcn_idle_work_handler(struct work_struct *work) 
		fences += fence[j];

	}



	if (fences == 0) {

	if (!fences && !atomic_read(&adev->vcn.total_submission_cnt)) {

		amdgpu_gfx_off_ctrl(adev, true);

		amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_VCN,

		       AMD_PG_STATE_GATE);
@@ -319,13 +322,14 @@ static void amdgpu_vcn_idle_work_handler(struct work_struct *work) 
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);



	if (set_clocks) {

	atomic_inc(&adev->vcn.total_submission_cnt);

	cancel_delayed_work_sync(&adev->vcn.idle_work);



	mutex_lock(&adev->vcn.vcn_pg_lock);

	amdgpu_gfx_off_ctrl(adev, false);

	amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_VCN,

	       AMD_PG_STATE_UNGATE);

	}



	if (adev->pg_flags & AMD_PG_SUPPORT_VCN_DPG)	{

		struct dpg_pause_state new_state;
@@ -345,10 +349,13 @@ 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)

{

	atomic_dec(&ring->adev->vcn.total_submission_cnt);



	schedule_delayed_work(&ring->adev->vcn.idle_work, VCN_IDLE_TIMEOUT);

}

drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h

+2 −0
Original line number Diff line number Diff line
@@ -200,6 +200,8 @@ 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;

	atomic_t		 total_submission_cnt;



	unsigned	harvest_config;

	int (*pause_dpg_mode)(struct amdgpu_device *adev,