[PATCH 4/6] dma-buf: Add an API for exporting sync files (v12)

[Simon Ser]

FWIW, I'm using this IOCTL in a wlroots patchset [1].

To detect support for this IOCTL, is there anything better than creating a
DMA-BUF and checking for ENOTTY? I'd like to disable explicit sync at init-time
if this is missing.

[1]: https://github.com/swaywm/wlroots/pull/3282