[Intel-gfx] [CI] drm/i915/userptr: Avoid struct_mutex recursion for mmu_invalidate_range_start

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-01-15 12:37:43)
> 
> On 15/01/2019 12:17, Chris Wilson wrote:
> > +             if (!unlock) {
> > +                     unlock = &mn->mm->i915->drm.struct_mutex;
> > +
> > +                     switch (mutex_trylock_recursive(unlock)) {
> > +                     default:
> > +                     case MUTEX_TRYLOCK_FAILED:
> > +                             if (!mutex_lock_killable_nested(unlock, I915_MM_SHRINKER))
> > +                                     return -EINTR;
> 
> Need to put object reference here I think.

I knew you would cause trouble, I knew it! You and your fancy error
reporting mutex_lock! :-p
-Chris