[Intel-gfx] [PATCH 2/2] drm/i915: Expose idle-delays to Kconfig

[Chris Wilson]

Quoting Tvrtko Ursulin (2017-12-22 11:52:28)
> 
> On 22/12/2017 11:33, Chris Wilson wrote:
> > +static inline long retire_delay(void)
> > +{
> > +     const long delay = msecs_to_jiffies(CONFIG_DRM_I915_GEM_RETIRE_DELAY);
> > +
> > +     if (CONFIG_DRM_I915_GEM_RETIRE_DELAY >= 1000)
> > +             return round_jiffies_up_relative(delay);
> 
> Round to a second? I am not sure we want that if exposing a tunable, but 
> at least need to say in Kconfig. But I don't see why we would round as I 
> said.

I think the principle of keeping timers aligned is good to keep, where
we can. Especially for idle-esque tasks where we don't want to wake the
CPU too often either. So I would rather explain the rounding behaviour
for timer-alignment for large delays in the Kconfig than lose it.
-Chris