[PATCH] drm/amd/amdgpu: Add mutex to protect IB resources

[Christian König]

Am 06.11.19 um 07:56 schrieb Jesse Zhang:
> Unloading driver has call trace when unloading happens
> 2s after loading driver.
>
> Since ring test are delayed after initializing driver,
> it is possible that driver has been unloaded before or
> while doing ring test.
>
> Add mutex to prevent ring test and driver finalization
> occurs at the same time and check before doing ring test
> if required resources still exist.

NAK, a mutex is the wrong approach.

You just need to add an flush_delayed_work(&adev->delayed_init_work) to 
amdgpu_device_fini().

Regards,
Christian.

>
> Change-Id: I27b52c2c630ad3853c6384e7b6906f0fae590ead
> Signed-off-by: Jesse Zhang <zhexi.zhang at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c     | 9 +++++++++
>   3 files changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 0469cc5..b825ad0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -923,6 +923,7 @@ struct amdgpu_device {
>   	struct amdgpu_ring		*rings[AMDGPU_MAX_RINGS];
>   	bool				ib_pool_ready;
>   	struct amdgpu_sa_manager	ring_tmp_bo;
> +	struct mutex			ib_lock;
>   
>   	/* interrupts */
>   	struct amdgpu_irq		irq;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index b2f38b0..8adbb25 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -2806,6 +2806,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>   	mutex_init(&adev->lock_reset);
>   	mutex_init(&adev->virt.dpm_mutex);
>   	mutex_init(&adev->psp.mutex);
> +	mutex_init(&adev->ib_lock);
>   
>   	r = amdgpu_device_check_arguments(adev);
>   	if (r)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> index d121bbd..ef5339e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> @@ -317,10 +317,12 @@ int amdgpu_ib_pool_init(struct amdgpu_device *adev)
>    */
>   void amdgpu_ib_pool_fini(struct amdgpu_device *adev)
>   {
> +	mutex_lock(&adev->ib_lock);
>   	if (adev->ib_pool_ready) {
>   		amdgpu_sa_bo_manager_fini(adev, &adev->ring_tmp_bo);
>   		adev->ib_pool_ready = false;
>   	}
> +	mutex_unlock(&adev->ib_lock);
>   }
>   
>   /**
> @@ -364,6 +366,11 @@ int amdgpu_ib_ring_tests(struct amdgpu_device *adev)
>   		struct amdgpu_ring *ring = adev->rings[i];
>   		long tmo;
>   
> +		if (adev->shutdown) {
> +			DRM_INFO("Device finalized, skip unfinished ring test\n");
> +			return 0;
> +		}
> +
>   		/* KIQ rings don't have an IB test because we never submit IBs
>   		 * to them and they have no interrupt support.
>   		 */
> @@ -381,7 +388,9 @@ int amdgpu_ib_ring_tests(struct amdgpu_device *adev)
>   		else
>   			tmo = tmo_gfx;
>   
> +		mutex_lock(&adev->ib_lock);
>   		r = amdgpu_ring_test_ib(ring, tmo);
> +		mutex_unlock(&adev->ib_lock);
>   		if (!r) {
>   			DRM_DEV_DEBUG(adev->dev, "ib test on %s succeeded\n",
>   				      ring->name);