On Sat, Feb 9, 2019 at 12:54 PM Chen Yu <yu.c.chen@xxxxxxxxx> 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.mzt@xxxxxxxxx> > Originally-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> > Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx> > --- > 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(); Well, update_turbo_state() should handle the case at hand already. That's what it's for actually: It checks if MSR_IA32_MISC_ENABLE_TURBO_DISABLE is set and sets global.turbo_disabled is that's the case. Why isn't that sufficient? > + max_freq = intel_pstate_get_max_freq(cpu); > + > + if (acpi_ppc && policy->max == policy->cpuinfo.max_freq && > + max_freq != policy->cpuinfo.max_freq) { > + /* > + * System was not running under any constraints, but the > + * current max possible frequency is changed. So reset > + * policy limits. > + */ > + policy->cpuinfo.max_freq = policy->max = max_freq; > + } Why does policy->cpuinfo.max_freq need to be updated? > + > cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, > - intel_pstate_get_max_freq(cpu)); > + max_freq); > > if (policy->policy != CPUFREQ_POLICY_POWERSAVE && > policy->policy != CPUFREQ_POLICY_PERFORMANCE) > --
