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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-11-17 22:47:47 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-11-17 22:47:47 +0100 |
| commit | d0ea59e188941417a9fb5898d894b3106a8ad313 (patch) | |
| tree | a5fdde28c81123f3221ca699914e8917441e6cd6 /include | |
| parent | cpufreq: dt: Add support for r8a7743 and r8a7745 (diff) | |
| download | linux-d0ea59e188941417a9fb5898d894b3106a8ad313.tar.xz linux-d0ea59e188941417a9fb5898d894b3106a8ad313.zip | |
cpufreq: intel_pstate: Request P-states control from SMM if needed
Currently, intel_pstate is unable to control P-states on my
IvyBridge-based Acer Aspire S5, because they are controlled by SMM
on that machine by default and it is necessary to request OS control
of P-states from it via the SMI Command register exposed in the ACPI
FADT. intel_pstate doesn't do that now, but acpi-cpufreq and other
cpufreq drivers for x86 platforms do.
Address this problem by making intel_pstate use the ACPI-defined
mechanism as well. However, intel_pstate is not modular and it
doesn't need the module refcount tricks played by
acpi_processor_notify_smm(), so export the core of this function
to it as acpi_processor_pstate_control() and make it call that.
[The changes in processor_perflib.c related to this should not
make any functional difference for the acpi_processor_notify_smm()
users].
To be safe, only call acpi_processor_notify_smm() from intel_pstate
if ACPI _PPC support is enabled in it.
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/acpi/processor.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/acpi/processor.h b/include/acpi/processor.h index f3db11c24654..dd0cb04046ce 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -249,6 +249,7 @@ extern int acpi_processor_register_performance(struct acpi_processor_performance *performance, unsigned int cpu); extern void acpi_processor_unregister_performance(unsigned int cpu); +int acpi_processor_pstate_control(void); /* note: this locks both the calling module and the processor module if a _PPC object exists, rmmod is disallowed then */ int acpi_processor_notify_smm(struct module *calling_module); |