On 14-02-19, 00:55, Yu Chen wrote: > Hi Viresh, > On Mon, Feb 11, 2019 at 04:03:07PM +0530, Viresh Kumar wrote: > > On 09-02-19, 20:02, Chen Yu wrote: > > > On Dell Inc. XPS13 9333, the BIOS changes the value of > > > MSR_IA32_MISC_ENABLE_TURBO_DISABLE at runtime (e.g., when > > > the power source changes), the maximum frequency of the > > > CPU is not updated accordingly. This is due to the policy's > > > cpuinfo.max is not updated when _PPC notifier fires. > > > > > > Fix this problem by updating the policy's cpuinfo.max > > > and broadcast the _PPC notifier to all online CPUs. > > > > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759 > > > Reported-and-tested-by: Gabriele Mazzotta <gabriele....@gmail.com> > > > Originally-by: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com> > > > Signed-off-by: Chen Yu <yu.c.c...@intel.com> > > > --- > > > drivers/acpi/processor_perflib.c | 16 ++++++++++++++-- > > > drivers/cpufreq/cpufreq.c | 2 ++ > > > drivers/cpufreq/intel_pstate.c | 15 ++++++++++++++- > > > 3 files changed, 30 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/acpi/processor_perflib.c > > > b/drivers/acpi/processor_perflib.c > > > index a303fd0e108c..737dbf5aa7f7 100644 > > > --- a/drivers/acpi/processor_perflib.c > > > +++ b/drivers/acpi/processor_perflib.c > > > @@ -63,6 +63,10 @@ module_param(ignore_ppc, int, 0644); > > > MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets > > > wrongly" \ > > > "limited by BIOS, this should help"); > > > > > > +static int broadcast_ppc; > > > +module_param(broadcast_ppc, int, 0644); > > > +MODULE_PARM_DESC(broadcast_ppc, "Broadcast the ppc to all online CPUs"); > > > + > > > #define PPC_REGISTERED 1 > > > #define PPC_IN_USE 2 > > > > > > @@ -180,8 +184,16 @@ void acpi_processor_ppc_has_changed(struct > > > acpi_processor *pr, int event_flag) > > > else > > > acpi_processor_ppc_ost(pr->handle, 0); > > > } > > > - if (ret >= 0) > > > - cpufreq_update_policy(pr->id); > > > + if (ret >= 0) { > > > + if (broadcast_ppc) { > > > + int cpu; > > > + > > > + for_each_possible_cpu(cpu) > > > + cpufreq_update_policy(cpu); > > > + } else { > > > + cpufreq_update_policy(pr->id); > > > + } > > > + } > > > } > > > > > > int acpi_processor_get_bios_limit(int cpu, unsigned int *limit) > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > > index e35a886e00bc..95e08816b512 100644 > > > --- a/drivers/cpufreq/cpufreq.c > > > +++ b/drivers/cpufreq/cpufreq.c > > > @@ -2237,6 +2237,8 @@ static int cpufreq_set_policy(struct cpufreq_policy > > > *policy, > > > > > > policy->min = new_policy->min; > > > policy->max = new_policy->max; > > > + policy->cpuinfo.max_freq = new_policy->cpuinfo.max_freq; > > > + policy->cpuinfo.min_freq = new_policy->cpuinfo.min_freq; > > > trace_cpu_frequency_limits(policy); > > > > > > policy->cached_target_freq = UINT_MAX; > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > b/drivers/cpufreq/intel_pstate.c > > > index dd66decf2087..e1881313c396 100644 > > > --- a/drivers/cpufreq/intel_pstate.c > > > +++ b/drivers/cpufreq/intel_pstate.c > > > @@ -2081,11 +2081,24 @@ static void intel_pstate_adjust_policy_max(struct > > > cpufreq_policy *policy, > > > > > > static int intel_pstate_verify_policy(struct cpufreq_policy *policy) > > > { > > > + int max_freq; > > > struct cpudata *cpu = all_cpu_data[policy->cpu]; > > > > > > update_turbo_state(); > > > + max_freq = intel_pstate_get_max_freq(cpu); > > > + > > > + if (acpi_ppc && policy->max == policy->cpuinfo.max_freq && > > > > Why do have this check for policy->max here ? > > > Thanks for looking at this change, I've replied to another email in detail of > the scenario that, this is due to corner case that if the system boots > with battery and plug the AC after boot up, the cpufreq max limit will not > increase even the turbo has been enabled after the AC plugged.
Yeah, but I asked a different question I believe, why is this comparison necessary ? policy->max == policy->cpuinfo.max_freq -- viresh
