[PATCH] drm/radeon/pm: autoswitch power state when in balanced mode

[Daniel Vetter]

On Mon, Oct 24, 2016 at 12:41:04PM -0400, Alex Deucher wrote:
> On Mon, Oct 24, 2016 at 5:46 AM, Christian König
> <christian.koenig at amd.com> wrote:
> > Am 23.10.2016 um 01:05 schrieb Lucas Stach:
> >>
> >> The current default of always using the performance power state leads
> >> to increased power consumption of mobile devices, which have a dedicated
> >> battery power state. Switch between the performance and battery power
> >> state automatically, dpending on the current AC power status, when the
> >> user asked for the balanced power state.
> >>
> >> The user can still override this logic by asking for the performance
> >> or battery power state explicitly.
> >>
> >> Signed-off-by: Lucas Stach <dev at lynxeye.de>
> >
> >
> > Nice addition, the only thing I can of hand see is that you probably want to
> > remove the "balanced states don't exist at the moment" comment when you
> > actually implement them (or abuse them).
> >
> > Apart from that I'm not so deep into the PM stuff, so patch is only
> > Acked-by: Christian König <christian.koenig at amd.com>.
> 
> IIRC, I had a similar patch years ago, and it was generally shot down
> since it moved policy into the driver.  Also, certain userspace
> packages like tlp do this already.  That said, I'm happy to apply it
> if there are no objections.

tbh I've stopped ignoring the "policy belongs into userspace" people for
areas where it essentially boils down to "we don't want to tune the hw
properly since it means more code is run and probably more bugs". I think
stuff like officially recommending that everyone run the autotune step of
powertop is just plain silly (and yes I'm argueing against my employer
here). We're trying to enable as much as possible by default (when it
makes sense), unfortunately there's many features with known bugs still :(

Anyway +1 from me for great defaults and auto-tuning drivers out of the
box. We're the kernel driver people, if we don't know how to best use the
hw, who else will? Certainly not users, and cargo-culting scripts doesn't
scale.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch