From: Jerome Glisse jglisse@redhat.com
Lock/unlock mutex in proper order to avoid deadlock in case of GPU reset triggered from VM code path.
Cc: stable@vger.kernel.org [3.5] Signed-off-by: Jerome Glisse jglisse@redhat.com --- drivers/gpu/drm/radeon/radeon_gart.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c index b372005..7eabb59 100644 --- a/drivers/gpu/drm/radeon/radeon_gart.c +++ b/drivers/gpu/drm/radeon/radeon_gart.c @@ -508,14 +508,19 @@ static void radeon_vm_unbind_locked(struct radeon_device *rdev, while (vm->fence) { int r; r = radeon_fence_wait(vm->fence, false); - if (r) + if (r) { DRM_ERROR("error while waiting for fence: %d\n", r); + } if (r == -EDEADLK) { + /* release mutex and lock in right order */ mutex_unlock(&rdev->vm_manager.lock); + mutex_unlock(&vm->mutex); r = radeon_gpu_reset(rdev); mutex_lock(&rdev->vm_manager.lock); - if (!r) + mutex_lock(&vm->mutex); + if (!r) { continue; + } } break; } @@ -551,7 +556,9 @@ void radeon_vm_manager_fini(struct radeon_device *rdev) mutex_lock(&rdev->vm_manager.lock); /* unbind all active vm */ list_for_each_entry_safe(vm, tmp, &rdev->vm_manager.lru_vm, list) { + mutex_lock(&vm->mutex); radeon_vm_unbind_locked(rdev, vm); + mutex_unlock(&vm->mutex); } rdev->vm_manager.funcs->fini(rdev); mutex_unlock(&rdev->vm_manager.lock);