[Intel-gfx] [PATCH 35/39] drm/i915: Pin pages before waiting

[Chris Wilson]

Quoting Matthew Auld (2019-06-14 20:53:26)
> On Fri, 14 Jun 2019 at 08:11, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > @@ -67,10 +61,17 @@ i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
> >          * continue to assume that the obj remained out of the CPU cached
> >          * domain.
> >          */
> > -       ret = i915_gem_object_pin_pages(obj);
> > +       ret = i915_gem_object_pin_pages_async(obj);
> >         if (ret)
> >                 return ret;
> >
> > +       ret = i915_gem_object_wait(obj,
> > +                                  I915_WAIT_INTERRUPTIBLE |
> > +                                  (write ? I915_WAIT_ALL : 0),
> > +                                  MAX_SCHEDULE_TIMEOUT);
> > +       if (ret)
> > +               goto out_unpin;
> > +
> 
> Do we somehow propagate a potential error from a worker to the
> object_wait()? Or should we be looking at obj->mm.pages here?

Yeah, I've propagated such errors elsewhere (principally along the
fences). What you are suggesting is tantamount to making
i915_gem_object_wait() report an error, and I have bad memories from all
the unhandled -EIO in the past. However, that feels the natural thing to
do, so lets give it a whirl.
-Chris