linux-kernel - Re: [PATCH 0/2] intel_pstate: fix turbo not being used after a processor is rebooted

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Date:   Fri, 23 Dec 2022 10:10:26 -0800
From:   srinivas pandruvada <srinivas.pandruvada@...ux.intel.com>
To:     Pratyush Yadav <ptyadav@...zon.de>
Cc:     linux-pm@...r.kernel.org, "Rafael J. Wysocki" <rafael@...nel.org>,
        Len Brown <lenb@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Robert Moore <robert.moore@...el.com>,
        linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
        devel@...ica.org
Subject: Re: [PATCH 0/2] intel_pstate: fix turbo not being used after a
 processor is rebooted

Hi Pratyush,

On Thu, 2022-12-22 at 11:39 +0100, Pratyush Yadav wrote:
> 
> Hi Srinivas,
> 
> On Wed, Dec 21 2022, srinivas pandruvada wrote:
> > On Wed, 2022-12-21 at 16:52 +0100, Pratyush Yadav wrote:
> > > When a processor is brought offline and online again, it is
> > > unable to
> > > use Turbo mode because the _PSS table does not contain the whole
> > > turbo
> > > frequency range, but only +1 MHz above the max non-turbo
> > > frequency.
> > > This
> > > causes problems when ACPI processor driver tries to set frequency
> > > constraints. See patch 2 for more details.
> > > 
I can reproduce on a Broadwell server platform. But not on a client
system with acpi_ppc usage.

Need to check what change broke this.

Thanks,
Srinivas

> > 
> > Thanks,
> > Srinivas
> > 
> > > Pratyush Yadav (2):
> > >   acpi: processor: allow fixing up the frequency for a
> > > performance
> > > state
> > >   cpufreq: intel_pstate: use acpi perflib to update turbo
> > > frequency
> > > 
> > >  drivers/acpi/processor_perflib.c | 40
> > > ++++++++++++++++++++++++++++++++
> > >  drivers/cpufreq/intel_pstate.c   |  5 ++--
> > >  include/acpi/processor.h         |  2 ++
> > >  3 files changed, 45 insertions(+), 2 deletions(-)
> > > 
> > > --
> > > 2.38.1
> > > 
> > 
>