Re: [PATCH v4 10/38] drm/i915: Force MMIO flips when scheduler enabled

Chris Wilson
2016-01-11T22:16:50Z

On Mon, Jan 11, 2016 at 06:42:39PM +0000, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
>
> MMIO flips are the preferred mechanism now but more importantly,

Says who?

> pipe
> based flips cause issues for the scheduler. Specifically, submitting
> work to the rings around the side of the scheduler could cause that
> work to be lost if the scheduler generates a pre-emption event on that
> ring.

That just says that you haven't designed for the ability to schedule a
flip into the scheduler, including handling the priority bump that might
required to hit the deadline.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre