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

[Michel Thierry]

On 12/04/17 09:22, Michel Thierry wrote:
> On 12/04/17 08:58, Chris Wilson wrote:
>> 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?
>
> A bit unrelated, but should intel_guc_reset be intel_reset_guc instead?
> Here we're trying to reset the microcontroller, not asking guc to do a
> reset.

Ping?

Anyone unlucky enough to be using GuC submission should be seeing this 
warning when the firmware has to be reloaded (for example after any 
i-g-t hang test).

I still think the function should be renamed to _reset_guc though, since 
it's the hw reseting the guc, not the other way around.

Acked-by: Michel Thierry <michel.thierry at intel.com>