Re: [PATCH v4 02/38] drm/i915: Explicit power enable during deferred context initialisation

John Harrison
2016-01-12T11:11:21Z

On 12/01/2016 00:20, Chris Wilson wrote:
> On Mon, Jan 11, 2016 at 06:42:31PM +0000, John.C.Harrison@Intel.com wrote:
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> A later patch in this series re-organises the batch buffer submission
>> code. Part of that is to reduce the scope of a pm_get/put pair.
>> Specifically, they previously wrapped the entire submission path from
>> the very start to the very end, now they only wrap the actual hardware
>> submission part in the back half.
> However, as you haven't fixed the ordering issue that requires rpm_get
> before struct_mutex, this is broken.
Why does 'intel_runtime_pm_get' require the struct mutex to be held? It
has certainly not complained at me about trying to do stuff without it.

> When we have rpm fixed, you don't
> need this patch as we can take the wakeref around the GSM access itself.
> We still want the prolonged rpm wakeref for the GPU activity, ofc.
> -Chris
>