[Intel-gfx] [PATCH 6/8] drm/i915/guc: Keep the engine awake until the tasklet is idle

[Daniele Ceraolo Spurio]

On 8/12/19 3:44 AM, Chris Wilson wrote:
> Quoting Chris Wilson (2019-08-12 10:10:43)
>> For the guc, we need to keep the engine awake (and not parked) and not
>> just the gt. If we let the engine park, we disable the irq and stop
>> processing the tasklet, leaving state outstanding inside the tasklet.
>>
>> The downside is, of course, we now have to wait until the tasklet is run
>> before we consider the engine idle.
> 
> Fwiw, because of this I think it may be preferable to keep to using GT
> pm for the tasklet; and apply Daniele's patch to keep
> NEEDS_BREADCRUMB_TASKLET set (which is the right thing to do anyway now
> that we stop switching between submission modes).
> -Chris
> 

Given that the GuC submission code is about to undergo a rework I 
believe it'd be better to keep the fix contained to the GuC side of 
things for now and avoid impacting the more general request paths (i.e. 
patch 4 in this series, unless you still want that for other reasons). 
I'll clean up and send the other patch.

Daniele