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From: Erwan Velu <erwanaliasr1@gmail.com>
Date: Wed, 10 Jan 2024 18:49:27 +0100
Message-ID: <CAL2Jzuzq-HVnhGZ8W0bSH6xibpYWXdXc30kC1Ub4vESfc4w7xA@mail.gmail.com>
Subject: Re: [PATCH 2/2] cpufreq/amd-pstate: Adding Zen4 support in introduction
To: Huang Rui <ray.huang@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>, Erwan Velu <e.velu@criteo.com>, 
	Viresh Kumar <viresh.kumar@linaro.org>, 
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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> How about modifying here as "partial Zen2, Zen3, and future processors"?
And all processors starting Zen4 ?

Le mer. 10 janv. 2024 =C3=A0 18:19, Huang Rui <ray.huang@amd.com> a =C3=A9c=
rit :
>
> On Wed, Jan 10, 2024 at 10:21:20PM +0800, Rafael J. Wysocki wrote:
> > On Tue, Jan 9, 2024 at 6:58=E2=80=AFPM Erwan Velu <erwanaliasr1@gmail.c=
om> wrote:
> > >
> > > amd-pstate is implemented on Zen4, adding this architecture in the
> > > introduction.
> > >
> > > Signed-off-by: Erwan Velu <e.velu@criteo.com>
> > > ---
> > >  drivers/cpufreq/amd-pstate.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstat=
e.c
> > > index 1f6186475715..9a8d083f6ba5 100644
> > > --- a/drivers/cpufreq/amd-pstate.c
> > > +++ b/drivers/cpufreq/amd-pstate.c
> > > @@ -14,7 +14,7 @@
> > >   * communicate the performance hints to hardware.
> > >   *
> > >   * AMD P-State is supported on recent AMD Zen base CPU series includ=
e some of
> > > - * Zen2 and Zen3 processors. _CPC needs to be present in the ACPI ta=
bles of AMD
> > > + * Zen2, Zen3 and Zen4 processors. _CPC needs to be present in the A=
CPI tables of AMD
> >
> > IMO, it would be really nice to avoid extending this line so much, but
> > this is up to the AMD people.
>
> Agree. Actually, we will use this driver for all future AMD CPU generatio=
ns
> that starts from paritial Zen2.
>
> >
> > Also, while you are at it, "include" in the first sentence should be
> > "including" and a new paragraph after "processors." would make this
> > comment easier to follow from the logical standpoint, because the
> > first sentence is about the supported platforms and the second one is
> > about additional requirements (ie. something else).
> >
>
> How about modifying here as "partial Zen2, Zen3, and future processors"?
>
> Thanks,
> Ray
>
> > >   * P-State supported system. And there are two types of hardware imp=
lementations
> > >   * for AMD P-State: 1) Full MSR Solution and 2) Shared Memory Soluti=
on.
> > >   * X86_FEATURE_CPPC CPU feature flag is used to distinguish the diff=
erent types.
> > > --