[PATCH] ACPI / processor: Do not request ACPI cpufreq module directly

From: Rafael J. Wysocki
Date: Sun Oct 27 2013 - 21:09:08 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Function acpi_processor_load_module() used by the ACPI processor
driver can only really work if the acpi-cpufreq module is available
when acpi_processor_start() is executed which usually is not the case
for systems loading the processor driver module from an initramfs.

Moreover, that used to be a hackish workaround for module autoloading
issues, but udev loads acpi-cpufreq just fine nowadays, so that
function isn't really necessary any more. For this reason, drop
acpi_processor_load_module() entirely.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/processor_driver.c | 1 -
drivers/acpi/processor_perflib.c | 22 ----------------------
include/acpi/processor.h | 1 -
3 files changed, 24 deletions(-)

Index: linux-pm/drivers/acpi/processor_driver.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_driver.c
+++ linux-pm/drivers/acpi/processor_driver.c
@@ -171,7 +171,6 @@ static int __acpi_processor_start(struct

#ifdef CONFIG_CPU_FREQ
acpi_processor_ppc_has_changed(pr, 0);
- acpi_processor_load_module(pr);
#endif
acpi_processor_get_throttling_info(pr);

Index: linux-pm/drivers/acpi/processor_perflib.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_perflib.c
+++ linux-pm/drivers/acpi/processor_perflib.c
@@ -235,28 +235,6 @@ 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;
Index: linux-pm/include/acpi/processor.h
===================================================================
--- linux-pm.orig/include/acpi/processor.h
+++ linux-pm/include/acpi/processor.h
@@ -225,7 +225,6 @@ struct acpi_processor_errata {
} piix4;
};

-extern void acpi_processor_load_module(struct acpi_processor *pr);
extern int acpi_processor_preregister_performance(struct
acpi_processor_performance
__percpu *performance);

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