Messages in this thread | | | Date | Tue, 12 Jan 2021 23:03:40 +0800 | From | Chen Yu <> | Subject | Re: [PATCH][v3] cpufreq: intel_pstate: Get percpu max freq via HWP MSR register if available |
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On Tue, Jan 12, 2021 at 02:52:50PM +0100, Rafael J. Wysocki wrote: > On Tue, Jan 12, 2021 at 6:19 AM Chen Yu <yu.c.chen@intel.com> wrote: > > > > Currently when turbo is disabled(either by BIOS or by the user), the > > intel_pstate driver reads the max non-turbo frequency from the package-wide > > MSR_PLATFORM_INFO(0xce) register. However on asymmetric platforms it is > > possible in theory that small and big core with HWP enabled might have > > different max non-turbo cpu frequency, because the MSR_HWP_CAPABILITIES > > is percpu scope according to Intel Software Developer Manual. > > > > The turbo max freq is already percpu basis in current code, thus make > > similar change to the max non-turbo frequency as well. > > > > Reported-by: Wendy Wang <wendy.wang@intel.com> > > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > > --- > > v2: Per Srinivas' suggestion, avoid duplicated assignment of max_pstate. > > v3: Per Rafael's suggestion, do not add new argument in intel_pstate_get_hwp_max() > > to avoid redundant local vars. > > Per Srinivas' suggestion, refined the commit log to reflect the 'non-turbo' > > max frequency. > > Looks good now, thanks! > > Is it needed in -stable and if so, which -stable series should it go into? > Yes, I think so, it should be Cc: stable@vger.kernel.org # 4.18+ as the HWP reading turbo frequency was firstly introduced in v4.18-rc2 and it was easier to be applied. BTW, this patch is on top of your previous patch set on intel_pstate clean up: https://patchwork.kernel.org/project/linux-pm/list/?series=410797
thanks, Chenyu
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