linux/drivers/cpufreq/cpufreq_powersave.c
Dominik Brodowski 2d06d8c49a [CPUFREQ] use dynamic debug instead of custom infrastructure
With dynamic debug having gained the capability to report debug messages
also during the boot process, it offers a far superior interface for
debug messages than the custom cpufreq infrastructure. As a first step,
remove the old cpufreq_debug_printk() function and replace it with a call
to the generic pr_debug() function.

How can dynamic debug be used on cpufreq? You need a kernel which has
CONFIG_DYNAMIC_DEBUG enabled.

To enabled debugging during runtime, mount debugfs and

$ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control

for debugging the complete "cpufreq" module. To achieve the same goal during
boot, append

	ddebug_query="module cpufreq +p"

as a boot parameter to the kernel of your choice.

For more detailled instructions, please see
Documentation/dynamic-debug-howto.txt

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-05-04 11:50:57 -04:00

65 lines
1.5 KiB
C

/*
* linux/drivers/cpufreq/cpufreq_powersave.c
*
* Copyright (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpufreq.h>
#include <linux/init.h>
static int cpufreq_governor_powersave(struct cpufreq_policy *policy,
unsigned int event)
{
switch (event) {
case CPUFREQ_GOV_START:
case CPUFREQ_GOV_LIMITS:
pr_debug("setting to %u kHz because of event %u\n",
policy->min, event);
__cpufreq_driver_target(policy, policy->min,
CPUFREQ_RELATION_L);
break;
default:
break;
}
return 0;
}
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
static
#endif
struct cpufreq_governor cpufreq_gov_powersave = {
.name = "powersave",
.governor = cpufreq_governor_powersave,
.owner = THIS_MODULE,
};
static int __init cpufreq_gov_powersave_init(void)
{
return cpufreq_register_governor(&cpufreq_gov_powersave);
}
static void __exit cpufreq_gov_powersave_exit(void)
{
cpufreq_unregister_governor(&cpufreq_gov_powersave);
}
MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
MODULE_DESCRIPTION("CPUfreq policy governor 'powersave'");
MODULE_LICENSE("GPL");
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
fs_initcall(cpufreq_gov_powersave_init);
#else
module_init(cpufreq_gov_powersave_init);
#endif
module_exit(cpufreq_gov_powersave_exit);