[Intel-gfx] [PATCH 1/4] drm/i915: Do a synchronous switch-to-kernel-context on idling

[Chris Wilson]

Quoting Chris Wilson (2019-03-08 12:44:16)
> Quoting Chris Wilson (2019-03-08 09:36:54)
> > +static bool switch_to_kernel_context_sync(struct drm_i915_private *i915)
> > +{
> > +       bool result = true;
> > +
> > +       /*
> > +        * Even if we fail to switch, give whatever is running a small chance
> > +        * to save itself before we report the failure. Yes, this may be a
> > +        * false positive due to e.g. ENOMEM, caveat emptor!
> > +        */
> > +       if (i915_gem_switch_to_kernel_context(i915))
> > +               result = false;
> > +
> > +       if (i915_gem_wait_for_idle(i915,
> > +                                  I915_WAIT_LOCKED |
> > +                                  I915_WAIT_FOR_IDLE_BOOST,
> > +                                  I915_GEM_IDLE_TIMEOUT))
> > +               result = false;
> > +
> > +       if (result) {
> > +               assert_kernel_context_is_current(i915);
> > +       } else {
> 
>         if (intel_has_gpu_reset()) {
> 
> > +               /* Forcibly cancel outstanding work and leave the gpu quiet. */
> > +               dev_err(i915->drm.dev,
> > +                       "Failed to idle engines, declaring wedged!\n");
> > +               GEM_TRACE_DUMP();
> 
>         }
> 
> To prevent it spewing just for gem_eio???
> 
> I think the error message is important, but gem_eio is a bit of an arm
> twister.

On the other hand, gem_eio does show that this can be user invoked so is
anything above a dev_notice() required?
-Chris