On Sun, Jun 3, 2012 at 10:09 AM, Christian König
<deathsim...@vodafone.de> wrote:
> Locking mutex in different orders just screams for
> deadlocks, and some testing showed that it is actually
> quite easy to trigger them.
>
> Signed-off-by: Christian König <deathsim...@vodafone.de>
Reviewed-by: Jerome Glisse <jgli...@redhat.com>
> Cc: sta...@vger.kernel.org
> ---
> drivers/gpu/drm/radeon/radeon_gart.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_gart.c
> b/drivers/gpu/drm/radeon/radeon_gart.c
> index 79db56e..59d4493 100644
> --- a/drivers/gpu/drm/radeon/radeon_gart.c
> +++ b/drivers/gpu/drm/radeon/radeon_gart.c
> @@ -476,12 +476,18 @@ int radeon_vm_bo_add(struct radeon_device *rdev,
>
> mutex_lock(&vm->mutex);
> if (last_pfn > vm->last_pfn) {
> - /* grow va space 32M by 32M */
> - unsigned align = ((32 << 20) >> 12) - 1;
> + /* release mutex and lock in right order */
> + mutex_unlock(&vm->mutex);
> radeon_mutex_lock(&rdev->cs_mutex);
> - radeon_vm_unbind_locked(rdev, vm);
> + mutex_lock(&vm->mutex);
> + /* and check again */
> + if (last_pfn > vm->last_pfn) {
> + /* grow va space 32M by 32M */
> + unsigned align = ((32 << 20) >> 12) - 1;
> + radeon_vm_unbind_locked(rdev, vm);
> + vm->last_pfn = (last_pfn + align) & ~align;
> + }
> radeon_mutex_unlock(&rdev->cs_mutex);
> - vm->last_pfn = (last_pfn + align) & ~align;
> }
> head = &vm->va;
> last_offset = 0;
> @@ -595,8 +601,8 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev,
> if (bo_va == NULL)
> return 0;
>
> - mutex_lock(&vm->mutex);
> radeon_mutex_lock(&rdev->cs_mutex);
> + mutex_lock(&vm->mutex);
> radeon_vm_bo_update_pte(rdev, vm, bo, NULL);
> radeon_mutex_unlock(&rdev->cs_mutex);
> list_del(&bo_va->vm_list);
> @@ -641,9 +647,8 @@ void radeon_vm_fini(struct radeon_device *rdev, struct
> radeon_vm *vm)
> struct radeon_bo_va *bo_va, *tmp;
> int r;
>
> - mutex_lock(&vm->mutex);
> -
> radeon_mutex_lock(&rdev->cs_mutex);
> + mutex_lock(&vm->mutex);
> radeon_vm_unbind_locked(rdev, vm);
> radeon_mutex_unlock(&rdev->cs_mutex);
>
> --
> 1.7.9.5
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
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