lkml.org 
[lkml]   [2019]   [May]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 3/3] thermal: cpu_cooling: Migrate to using the EM framework
On Tuesday 14 May 2019 at 07:17:37 (-0700), Eduardo Valentin wrote:
> Hey Quentin,
>
> On Tue, May 14, 2019 at 08:15:08AM +0100, Quentin Perret wrote:
> > Hi Eduardo,
> >
> > On Monday 13 May 2019 at 20:40:59 (-0700), Eduardo Valentin wrote:
> > > On Fri, May 03, 2019 at 10:44:09AM +0100, Quentin Perret wrote:
> > > > The newly introduced Energy Model framework manages power cost tables in
> > > > a generic way. Moreover, it supports a several types of models since the
> > > > tables can come from DT or firmware (through SCMI) for example. On the
> > > > other hand, the cpu_cooling subsystem manages its own power cost tables
> > > > using only DT data.
> > > >
> > > > In order to avoid the duplication of data in the kernel, and in order to
> > > > enable IPA with EMs coming from more than just DT, remove the private
> > > > tables from cpu_cooling.c and migrate it to using the centralized EM
> > > > framework.
> > > >
> > > > The case where the thermal subsystem is used without an Energy Model
> > > > (cpufreq_cooling_ops) is handled by looking directly at CPUFreq's
> > > > frequency table which is already a dependency for cpu_cooling.c anyway.
> > > > Since the thermal framework expects the cooling states in a particular
> > > > order, bail out whenever the CPUFreq table is unsorted, since that is
> > > > fairly uncommon in general, and there are currently no users of
> > > > cpu_cooling for this use-case.
> > >
> > > Will this break DT in any way? After this change, are the existing DTs
> > > still compatible with this cpu cooling?
> >
> > Yes, all existing DTs stay compatible with this CPU cooling. The EM can
> > still be built using the 'dynamic-power-coefficient' DT property thanks
> > to the recently introduced dev_pm_opp_of_register_em() helper, see
> > a4f342b9607d ("PM / OPP: Introduce a power estimation helper"). And all
> > relevant cpufreq drivers have already been updated to use that function.
>
> I see..
>
> >
> > So, this patch should cause no functional change for all existing users.
> > It's really just plumbing. I can probably explain that better in this
> > commit message rather than the cover letter if you feel it is necessary.
> >
>
> Yes I would prefer if this info goes into the commit message.

No problem, will do in v4.

Thanks,
Quentin

\
 
 \ /
  Last update: 2019-05-14 16:21    [W:0.034 / U:4.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site