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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-01-14 18:08:14 +0400 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2013-02-08 04:44:31 +0400 |
| commit | ff7c60c580d9722f820d85c9c58ca55ecc1ee7c4 (patch) | |
| tree | b015a7739098ecf33a478b40103ab472fe0531fc /drivers/gpu/drm | |
| parent | 6bacaa9ddacb71c691d32c678d37bc59ffc71fac (diff) | |
| download | linux-ff7c60c580d9722f820d85c9c58ca55ecc1ee7c4.tar.xz | |
drm/ttm: fix fence locking in ttm_buffer_object_transfer, 2nd try
This fixes up
commit e8e89622ed361c46bf90ba4828e685a8b603f7e5
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
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@gmail.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo_util.c | 13 |
1 files 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 44420fca7dfa..8be35c809c7b 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -429,7 +429,7 @@ 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; @@ -448,7 +448,12 @@ 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; @@ -661,13 +666,11 @@ 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; |