Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit db1fc97c authored by Chris Wilson's avatar Chris Wilson Committed by Gustavo Padovan
Browse files

dma-buf/sync_file: Allow multiple sync_files to wrap a single dma-fence 



Up until recently sync_file were create to export a single dma-fence to
userspace, and so we could canabalise a bit insie dma-fence to mark
whether or not we had enable polling for the sync_file itself. However,
with the advent of syncobj, we do allow userspace to create multiple
sync_files for a single dma-fence. (Similarly, that the sw-sync
validation framework also started returning multiple sync-files wrapping
a single dma-fence for a syncpt also triggering the problem.)

This patch reverts my suggestion in commit e2416553
("dma-buf/sync_file: only enable fence signalling on poll()") to use a
single bit in the shared dma-fence and restores the sync_file->flags for
tracking the bits individually.

Reported-by: default avatarGustavo Padovan <gustavo.padovan@collabora.com>
Fixes: f1e8c671 ("dma-buf/sw-sync: Use an rbtree to sort fences in the timeline")
Fixes: e9083420 ("drm: introduce sync objects (v4)")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: dri-devel@lists.freedesktop.org
Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.13-rc1+
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170728212951.7818-1-chris@chris-wilson.co.uk
parent 8312a3fe

drivers/dma-buf/sync_file.c

+3 −2
Original line number Diff line number Diff line
@@ -304,7 +304,7 @@ static int sync_file_release(struct inode *inode, struct file *file) 
{

	struct sync_file *sync_file = file->private_data;



	if (test_bit(POLL_ENABLED, &sync_file->fence->flags))

	if (test_bit(POLL_ENABLED, &sync_file->flags))

		dma_fence_remove_callback(sync_file->fence, &sync_file->cb);

	dma_fence_put(sync_file->fence);

	kfree(sync_file);
@@ -318,7 +318,8 @@ static unsigned int sync_file_poll(struct file *file, poll_table *wait) 


	poll_wait(file, &sync_file->wq, wait);



	if (!test_and_set_bit(POLL_ENABLED, &sync_file->fence->flags)) {

	if (list_empty(&sync_file->cb.node) &&

	    !test_and_set_bit(POLL_ENABLED, &sync_file->flags)) {

		if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,

					   fence_check_cb_func) < 0)

			wake_up_all(&sync_file->wq);

include/linux/sync_file.h

+2 −1
Original line number Diff line number Diff line
@@ -43,12 +43,13 @@ struct sync_file { 
#endif



	wait_queue_head_t	wq;

	unsigned long		flags;



	struct dma_fence	*fence;

	struct dma_fence_cb cb;

};



#define POLL_ENABLED DMA_FENCE_FLAG_USER_BITS

#define POLL_ENABLED 0



struct sync_file *sync_file_create(struct dma_fence *fence);

struct dma_fence *sync_file_get_fence(int fd);