Re: [PATCH 1/7] drm/i915: Relax RPS contraints to allows setting minfreq on idle

Jesse Barnes
2015-03-09T15:37:10Z

On 03/06/2015 07:06 AM, Chris Wilson wrote:
> When we idle, we set the GPU frequency to the hardware minimum (not user
> minimum). We introduce a new variable to distinguish between the
> different roles, and to allow easy tuning of the idle frequency without
> impacting over aspects of RPS. Setting the minimum frequency should be a
> safety blanket as the pcu on the GPU should be power gating itself
> anyway. However, in order for us to do set the absolute minimum
> frequency, we need to relax a few of our assertions that we do not
> exceed the user limits.
>
> v2: Add idle_freq
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Arg, we still need some way of getting numbers (both perf and power) for
these kinds of changes across a variety of workloads.

Wendy, is that something you can do manually? Comparing BYT with and
without these patches across your power/perf tests?

Thanks,
Jesse