diff options
Diffstat (limited to 'drivers/acpi/processor_perflib.c')
| -rw-r--r-- | drivers/acpi/processor_perflib.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 85b32376dad..0af48a8554c 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -240,6 +240,28 @@ void acpi_processor_ppc_exit(void) acpi_processor_ppc_status &= ~PPC_REGISTERED; } +/* + * Do a quick check if the systems looks like it should use ACPI + * cpufreq. We look at a _PCT method being available, but don't + * do a whole lot of sanity checks. + */ +void acpi_processor_load_module(struct acpi_processor *pr) +{ + static int requested; + acpi_status status = 0; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + + if (!arch_has_acpi_pdc() || requested) + return; + status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer); + if (!ACPI_FAILURE(status)) { + printk(KERN_INFO PREFIX "Requesting acpi_cpufreq\n"); + request_module_nowait("acpi_cpufreq"); + requested = 1; + } + kfree(buffer.pointer); +} + static int acpi_processor_get_performance_control(struct acpi_processor *pr) { int result = 0; |