diff options
| author | Tim Gardner <tim.gardner@canonical.com> | 2012-04-24 11:47:18 -0600 |
|---|---|---|
| committer | John Rigby <john.rigby@linaro.org> | 2012-06-25 15:02:24 -0600 |
| commit | 47b844782eab75e1e6f077f66e36847ee7213ffd (patch) | |
| tree | c2c94ec1a7cd180e0e60bb67422d3e3c0b6d709e | |
| parent | 3645868a274e195fbe641cd4f219bfbbc06b5a2b (diff) | |
UBUNTU: SAUCE: Allow filtering of cpufreq drivers
BugLink: http://bugs.launchpad.net/bugs/984288
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 | ||||
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 22 |
2 files changed, 25 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d79efa33735..ef9af9a052c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -588,6 +588,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. /proc/<pid>/coredump_filter. See also Documentation/filesystems/proc.txt. + cpufreq_driver= [X86] Allow only the named cpu frequency scaling driver + to register. Example: cpufreq_driver=powernow-k8 + Format: { none | STRING } + cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 7f2f149ae40..222966f3443 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1817,6 +1817,20 @@ static struct notifier_block __refdata cpufreq_cpu_notifier = { * REGISTER / UNREGISTER CPUFREQ DRIVER * *********************************************************************/ +static char cpufreq_driver_name[CPUFREQ_NAME_LEN]; + +static int __init cpufreq_driver_setup(char *str) +{ + strlcpy(cpufreq_driver_name, str, CPUFREQ_NAME_LEN); + return 1; +} + +/* + * Set this name to only allow one specific cpu freq driver, e.g., + * cpufreq_driver=powernow-k8 + */ +__setup("cpufreq_driver=", cpufreq_driver_setup); + /** * cpufreq_register_driver - register a CPU Frequency driver * @driver_data: A struct cpufreq_driver containing the values# @@ -1839,7 +1853,13 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data) ((!driver_data->setpolicy) && (!driver_data->target))) return -EINVAL; - pr_debug("trying to register driver %s\n", driver_data->name); + pr_debug("trying to register driver %s, cpufreq_driver=%s\n", + driver_data->name, cpufreq_driver_name); + + if (cpufreq_driver_name[0]) + if (!driver_data->name || + strcmp(cpufreq_driver_name, driver_data->name)) + return -EINVAL; if (driver_data->setpolicy) driver_data->flags |= CPUFREQ_CONST_LOOPS; |