[Intel-gfx] [PATCH v3 1/3] drm/i915: Stop using RP_DOWN_EI on Baytrail

[Chris Wilson]

On Fri, Mar 10, 2017 at 04:10:29PM +0200, Mika Kuoppala wrote:
> Chris Wilson <chris at chris-wilson.co.uk> writes:
> 
> > On Baytrail, we manually calculate busyness over the evaluation interval
> > to avoid issues with miscaluations with RC6 enabled. However, it turns
> > out that the DOWN_EI interrupt generator is completely bust - it
> > operates in two modes, continuous or never. Neither of which are
> > conducive to good behaviour. Stop unmask the DOWN_EI interrupt and just
> > compute everything from the UP_EI which does seem to correspond to the
> > desired interval.
> >
> > v2: Fixup gen6_rps_pm_mask() as well
> > v3: Inline vlv_c0_above() to combine the now identical elapsed
> > calculation for up/down and simplify the threshold testing
> >
> > Fixes: 43cf3bf084ba ("drm/i915: Improved w/a for rps on Baytrail")
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> > Cc: <stable at vger.kernel.org> # v4.1+
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com>

Many thanks for the review. Pushed, active rps on byt is going to upset
the apple cart slightly :|
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre