[Intel-gfx] [PATCH 3/4] drm/i915: Reload PD tables after semaphore wait on gen8

[Chris Wilson]

On Mon, Apr 11, 2016 at 10:34:14AM +0300, Ville Syrjälä wrote:
> On Sat, Apr 09, 2016 at 11:14:45AM +0100, Chris Wilson wrote:
> > When the engine idles waiting upon a semaphore, it loses its
> > pagetables and we must reload them before executing the batch.
> 
> RCS shouldn't lose them IIRC, other engines yes. As I recall the
> other way to avoid this would be to prevent the engine from
> entering some power save mode during the wait, but I suppose
> that might come at a power cost.

Right, this only affects !RCS.
Just changing to if (ppgtt && waiter_req->engine->id != RCS)
would be enough. Care to give a r-b with that in place since you've
checked bspec? :)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre