[Intel-gfx] [PATCH 1/2] drm/i915/guc: Fix sleep under spinlock during reset

[Chris Wilson]

On Wed, Apr 12, 2017 at 04:48:42PM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Looks like intel_guc_reset had the ability to sleep under the
> uncore spinlock since forever but it wasn't detected until the
> recent changes annotated the wait for register with might_sleep.
> 
> I have fixed it by removing holding of the uncore spinlock over
> the call to gen6_hw_domain_reset, since I do not see that is
> really needed. But there is always a possibility I am missing
> some nasty detail so please double check.

Afaik, no we are not using the uncore.lock here to serialise resets so
yes we should be safe in dropping it.

Will the guc be coming under the same hw semaphore as gen8 per-engine
resets?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre