[PATCH 0/2][RFC v2] Update the cpuinfo.max when power supply changes

From: Chen Yu
Date: Thu Feb 28 2019 - 12:58:51 EST


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.

Firstly we should update the cpuinfo.max in this corner case,
secondly we should broadcast the _PPC notifier to all online
CPUs to keep information consistent.

Chen Yu (2):
ACPI: add "processor.broadcast_ppc" hook to broadcast _PPC
ACPI: Update cpuinfo.max after bootup if necessary

drivers/acpi/processor_perflib.c | 16 ++++++++++++++--
drivers/cpufreq/cpufreq.c | 2 ++
drivers/cpufreq/intel_pstate.c | 15 +++++++++++++--
3 files changed, 29 insertions(+), 4 deletions(-)

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2.17.1