Am 16.02.2017 um 12:39 schrieb Nicolai Hähnle:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>
> By using ttm_bo_init_reserved instead of the manual initialization of
> the reservation object, the reservation lock will be properly unlocked
> and destroyed when the TTM BO initialization fails.
>
> Actual deadlocks caused by the missing unlock should have been fixed
> by "drm/ttm: never add BO that failed to validate to the LRU list",
> superseding the flawed fix in commit 38fc4856ad98 ("drm/amdgpu: fix
> a potential deadlock in amdgpu_bo_create_restricted()").
>
> This change fixes remaining recursive locking errors that can be seen
> with lock debugging enabled, and avoids the error of freeing a locked
> mutex.
>
> As an additional minor bonus, buffers created with resv == NULL and
> the AMDGPU_GEM_CREATE_VRAM_CLEARED flag are now only added to the
> global LRU list after the fill commands have been issued.
>
> Fixes: 12a852219583 ("drm/amdgpu: improve AMDGPU_GEM_CREATE_VRAM_CLEARED handling (v2)")
> Signed-off-by: Nicolai Hähnle <nicolai.haehnle at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 17 ++++-------------
> 1 file changed, 4 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index c2e57f7..4d0536d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -395,19 +395,10 @@ int amdgpu_bo_create_restricted(struct amdgpu_device *adev,
> amdgpu_fill_placement_to_bo(bo, placement);
> /* Kernel allocation are uninterruptible */
>
> - if (!resv) {
> - bool locked;
> -
> - reservation_object_init(&bo->tbo.ttm_resv);
> - locked = ww_mutex_trylock(&bo->tbo.ttm_resv.lock);
> - WARN_ON(!locked);
> - }
> -
> initial_bytes_moved = atomic64_read(&adev->num_bytes_moved);
> - r = ttm_bo_init(&adev->mman.bdev, &bo->tbo, size, type,
> - &bo->placement, page_align, !kernel, NULL,
> - acc_size, sg, resv ? resv : &bo->tbo.ttm_resv,
> - &amdgpu_ttm_bo_destroy);
> + r = ttm_bo_init_reserved(&adev->mman.bdev, &bo->tbo, size, type,
> + &bo->placement, page_align, !kernel, NULL,
> + acc_size, sg, resv, &amdgpu_ttm_bo_destroy);
> amdgpu_cs_report_moved_bytes(adev,
> atomic64_read(&adev->num_bytes_moved) - initial_bytes_moved);
>
> @@ -433,7 +424,7 @@ int amdgpu_bo_create_restricted(struct amdgpu_device *adev,
> fence_put(fence);
> }
> if (!resv)
> - ww_mutex_unlock(&bo->tbo.resv->lock);
> + ttm_bo_unreserve(&bo->tbo);
You can just use amdgpu_bo_unreserve() here. With that fixed the whole
set is Reviewed-by: Christian König <christian.koenig at amd.com>.
Regards,
Christian.
> *bo_ptr = bo;
>
> trace_amdgpu_bo_create(bo);
