[Intel-gfx] [PATCH 3/4] drm/i915: HSW GT3 Slices: exec flag to warn kernel that userspace is using predication

Chris Wilson chris at chris-wilson.co.uk
Wed Oct 16 14:19:49 CEST 2013

On Wed, Oct 16, 2013 at 09:12:46AM -0300, Rodrigo Vivi wrote:
> >> +             dev_priv->gt_slices.forcing_full = true;
> >> +             i915_gt_full_immediate(dev, ring);
> >
> > What happens when this fails? If it only partially emits the commands,
> > etc.
> This is a very good question. If it fails, my only concern would be
> the sync between HSW_GT_SLICE_INFO and MI_PREDICATE_RESULT_2. But I
> don't know how to do this during the exec buf without delaying the
> execution. Do you have any suggestion?

Reduce the series of if() to just one, act upon the return value, only
set legacy_userspace_busy to true after making the change. It will
eventually get cleaned up if the dispatch later fails, but we must make
sure that we accurately track hardware state.

Chris Wilson, Intel Open Source Technology Centre

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