A race condition existed in gk20a_channel_semaphore_wait_fd().
In some instances the semaphore underlying the sync_fence being
waited on would have already signaled. This would cause the
subsequent sync_fence_wait_async() call to return 1 and do
nothing. Normally, the sync_fence_wait_async() call would
release the newly created semaphore but in the above case that
would not happen and hang any channel waiting on that semaphore.
To fix this problem if sync_fence_wait_async() returns 1
immediately release the newly created semaphore.
Bug 1604892
Change-Id: I1f5e811695bb099f71b7762835aba4a7e27362ec
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/935910
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
GVS: Gerrit_Virtual_Submit