[Intel-gfx] [PATCH v2] drm/i915: Keep the forcewake timer alive for 1ms past the most recent use

[Chris Wilson]

On Mon, May 15, 2017 at 02:20:24PM +0300, Mika Kuoppala wrote:
> Chris Wilson <chris at chris-wilson.co.uk> writes:
> > @@ -520,8 +527,10 @@ static void __intel_uncore_forcewake_put(struct drm_i915_private *dev_priv,
> >  		if (WARN_ON(domain->wake_count == 0))
> >  			continue;
> >  
> > -		if (--domain->wake_count)
> > +		if (--domain->wake_count) {
> > +			domain->active = true;
> 
> We dont wan't to set the active here for all domains that
> are going to power off, and delay their release for one timer tick
> to optimistically wait for next user?

If we hit zero, that implies there is no timer and so we will arm it for
1ms. The question amounts to whether we want it to run for a minimum of
2ms rather than 1ms.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre