diff options
| author | Andi Kleen <ak@linux.intel.com> | 2012-01-26 00:09:08 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-26 16:48:12 -0800 |
| commit | 9061e0e16700ef228837e96987ff51794c956197 (patch) | |
| tree | 53d2ffa0fbc64f404848f4bfeb964d84cf08de36 /drivers/acpi | |
| parent | b66b8b9a4a79087dde1b358a016e5c8739ccf186 (diff) | |
ACPI: Load acpi-cpufreq from processor driver automatically
The only left over hole in automatic cpufreq driver loading was the loading
of ACPI cpufreq. This driver should be loaded when ACPI supports a _PDC
method and the CPU vendor wants to use acpi cpufreq.
Simply add a request module call to the acpi processor core driver
when this is true. This seems like the simplest solution for this.
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/processor_driver.c | 1 | ||||
| -rw-r--r-- | drivers/acpi/processor_perflib.c | 22 |
2 files changed, 23 insertions, 0 deletions
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 0034ede3871..e6920d0aca5 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -497,6 +497,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device) #ifdef CONFIG_CPU_FREQ acpi_processor_ppc_has_changed(pr, 0); + acpi_processor_load_module(pr); #endif acpi_processor_get_throttling_info(pr); acpi_processor_get_limit_info(pr); 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; |