diff options
| author | Gustavo Padovan <gustavo.padovan@collabora.co.uk> | 2016-08-05 15:39:38 +0200 |
|---|---|---|
| committer | Sumit Semwal <sumit.semwal@linaro.org> | 2016-08-11 12:09:38 +0200 |
| commit | e24165537312723e2900831dd6e7415b8d85278c (patch) | |
| tree | 50fdfc4cbedb2b92a1a96c79141d0605ad63bf6e /drivers/dma-buf | |
| parent | Documentation: add doc for sync_file_get_fence() (diff) | |
| download | linux-e24165537312723e2900831dd6e7415b8d85278c.tar.xz linux-e24165537312723e2900831dd6e7415b8d85278c.zip | |
dma-buf/sync_file: only enable fence signalling on poll()
Signalling doesn't need to be enabled at sync_file creation, it is only
required if userspace waiting the fence to signal through poll().
Thus we delay fence_add_callback() until poll is called. It only adds the
callback the first time poll() is called. This avoid re-adding the same
callback multiple times.
v2: rebase and update to work with new fence support for sync_file
v3: use atomic operation to set enabled and protect fence_add_callback()
v4: use user bit from fence flags (comment from Chris Wilson)
v5: use ternary if on poll return (comment from Chris Wilson)
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
[sumits: remove unused var status]
Link: http://patchwork.freedesktop.org/patch/msgid/1470404378-27961-1-git-send-email-gustavo@padovan.org
Diffstat (limited to 'drivers/dma-buf')
| -rw-r--r-- | drivers/dma-buf/sync_file.c | 21 |
1 files changed, 8 insertions, 13 deletions
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c index 2873760e02a9..486d29c1a830 100644 --- a/drivers/dma-buf/sync_file.c +++ b/drivers/dma-buf/sync_file.c @@ -86,8 +86,6 @@ struct sync_file *sync_file_create(struct fence *fence) fence->ops->get_timeline_name(fence), fence->context, fence->seqno); - fence_add_callback(fence, &sync_file->cb, fence_check_cb_func); - return sync_file; } EXPORT_SYMBOL(sync_file_create); @@ -274,9 +272,6 @@ static struct sync_file *sync_file_merge(const char *name, struct sync_file *a, goto err; } - fence_add_callback(sync_file->fence, &sync_file->cb, - fence_check_cb_func); - strlcpy(sync_file->name, name, sizeof(sync_file->name)); return sync_file; @@ -291,7 +286,8 @@ static void sync_file_free(struct kref *kref) struct sync_file *sync_file = container_of(kref, struct sync_file, kref); - fence_remove_callback(sync_file->fence, &sync_file->cb); + if (test_bit(POLL_ENABLED, &sync_file->fence->flags)) + fence_remove_callback(sync_file->fence, &sync_file->cb); fence_put(sync_file->fence); kfree(sync_file); } @@ -307,17 +303,16 @@ static int sync_file_release(struct inode *inode, struct file *file) static unsigned int sync_file_poll(struct file *file, poll_table *wait) { struct sync_file *sync_file = file->private_data; - int status; poll_wait(file, &sync_file->wq, wait); - status = fence_is_signaled(sync_file->fence); + if (!test_and_set_bit(POLL_ENABLED, &sync_file->fence->flags)) { + if (fence_add_callback(sync_file->fence, &sync_file->cb, + fence_check_cb_func) < 0) + wake_up_all(&sync_file->wq); + } - if (status) - return POLLIN; - if (status < 0) - return POLLERR; - return 0; + return fence_is_signaled(sync_file->fence) ? POLLIN : 0; } static long sync_file_ioctl_merge(struct sync_file *sync_file, |