dma-buf/sync_file: Allow multiple sync_files to wrap a single dma-fence
authorChris Wilson <chris@chris-wilson.co.uk>
Fri, 28 Jul 2017 21:29:51 +0000 (22:29 +0100)
committerGustavo Padovan <gustavo.padovan@collabora.com>
Sat, 29 Jul 2017 14:10:52 +0000 (11:10 -0300)
commitdb1fc97ca0c0d3fdeeadf314d99a26188438940a
tree94aaa4762b384f31af39ba08fa6453f54c297237
parent8312a3fe84b96e30a010fa20f933606d976ac002
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 e24165537312
("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: Gustavo Padovan <gustavo.padovan@collabora.com>
Fixes: f1e8c67123cf ("dma-buf/sw-sync: Use an rbtree to sort fences in the timeline")
Fixes: e9083420bbac ("drm: introduce sync objects (v4)")
Signed-off-by: Chris 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: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170728212951.7818-1-chris@chris-wilson.co.uk
drivers/dma-buf/sync_file.c
include/linux/sync_file.h