This fixes up
commit e8e89622ed361c46bf90ba4828e685a8b603f7e5
Author: Daniel Vetter <daniel.vetter@xxxxxxxx>
Date: Tue Dec 18 22:25:11 2012 +0100
drm/ttm: fix fence locking in ttm_buffer_object_transfer
which leaves behind a might_sleep in atomic context, since the
fence_lock spinlock is held over a kmalloc(GFP_KERNEL) call. The fix
is to revert the above commit and only take the lock where we need it,
around the call to ->sync_obj_ref.
v2: Fixup things noticed by Maarten Lankhorst:
- Brown paper bag locking bug.
- No need for kzalloc if we clear the entire thing on the next line.
- check for bo->sync_obj (totally unlikely race, but still someone
else could have snuck in) and clear fbo->sync_obj if it's cleared
already.
Reported-by: Dave Airlie <airlied@xxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/ttm/ttm_bo_util.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index d73d6e3..544e407 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -422,7 +422,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_bo_driver *driver = bdev->driver;
- fbo = kzalloc(sizeof(*fbo), GFP_KERNEL);
+ fbo = kmalloc(sizeof(*fbo), GFP_KERNEL);
if (!fbo)
return -ENOMEM;
@@ -441,7 +441,12 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
fbo->vm_node = NULL;
atomic_set(&fbo->cpu_writers, 0);
- fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
+ spin_lock(&bdev->fence_lock);
+ if (bo->sync_obj)
+ fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
+ else
+ fbo->sync_obj = NULL;
+ spin_unlock(&bdev->fence_lock);
kref_init(&fbo->list_kref);
kref_init(&fbo->kref);
fbo->destroy = &ttm_transfered_destroy;
@@ -654,13 +659,11 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
*/
set_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
-
- /* ttm_buffer_object_transfer accesses bo->sync_obj */
- ret = ttm_buffer_object_transfer(bo, &ghost_obj);
spin_unlock(&bdev->fence_lock);
if (tmp_obj)
driver->sync_obj_unref(&tmp_obj);
+ ret = ttm_buffer_object_transfer(bo, &ghost_obj);
if (ret)
return ret;
--
1.7.10.4
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