On Sun, Aug 28, 2016 at 09:46:24PM +0100, Chris Wilson wrote: > +/* Setting I915_EXEC_FENCE_OUT causes the ioctl to return a sync_file fd > + * in the upper_32_bits(rsvd2) upon success. Ownership of the fd is given > + * to the caller, and it should be close() after use. (The fd is a regular > + * file descriptor and will be cleaned up on process termination. It holds > + * a reference to the request, but nothing else.) > + * > + * The sync_file fd can be combined with other sync_file and passed either > + * to execbuf using I915_EXEC_FENCE_IN, to atomic KMS ioctls (so that a flip > + * will only occur after this request completes), or to other devices. Addendum: Using I915_EXEC_FENCE_OUT requires use of DRM_IOCTL_I915_GEM_EXECBUFFER2_WR ioctl so that the result is written back to userspace. Failure to do so will cause the out-fence to always be reported as zero, and the real fence fd to be leaked. -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
