[PATCH 1/2] drm/ttm: add a way to bo_wait for either the last read or last write

[Marek Olšák]

On Fri, Oct 7, 2011 at 3:42 PM, Jerome Glisse <j.glisse at gmail.com> wrote:
> Forget to mention that we would need a new wait_fence ioctl to wait
> for a specific fence seq on a specific ring

We need a wait_fence ioctl anyway and even with a timeout parameter.
It's a mandatory OpenGL feature. r600g uses a loop with sched_yield
right now, which is like the worst implementation of wait_fence we can
have. r300g uses bo_wait for timeout == infinite, and a loop with
usleep for timeout != infinite.

Marek