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authorDirk Brandewie <dirk.brandewie@gmail.com>2013-02-15 22:55:10 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-02-15 22:55:10 +0100
commit6be264986152c498562f26b15ed73c70aa37ce48 (patch)
tree98d9a397ca627d67a9fbd117a23b8acbfd69622a
parentcpufreq / intel_pstate: Change to disallow module build (diff)
downloadlinux-6be264986152c498562f26b15ed73c70aa37ce48.tar.xz
linux-6be264986152c498562f26b15ed73c70aa37ce48.zip
cpufreq / intel_pstate: Add kernel command line option disable intel_pstate.
When intel_pstate is configured into the kernel it will become the preferred scaling driver for processors that it supports. Allow the user to override this by adding: intel_pstate=disable on the kernel command line. Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--Documentation/kernel-parameters.txt5
-rw-r--r--drivers/cpufreq/intel_pstate.c16
2 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 363e348bff9b..b335c456feb9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1131,6 +1131,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
0 disables intel_idle and fall back on acpi_idle.
1 to 6 specify maximum depth of C-state.
+ intel_pstate= [X86]
+ disable
+ Do not enable intel_pstate as the default
+ scaling driver for the supported processors
+
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
off disable Interrupt Remapping
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e87996355da0..096fde0ebcb5 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -773,11 +773,16 @@ static void intel_pstate_exit(void)
}
module_exit(intel_pstate_exit);
+static int __initdata no_load;
+
static int __init intel_pstate_init(void)
{
int rc = 0;
const struct x86_cpu_id *id;
+ if (no_load)
+ return -ENODEV;
+
id = x86_match_cpu(intel_pstate_cpu_ids);
if (!id)
return -ENODEV;
@@ -802,6 +807,17 @@ out:
}
device_initcall(intel_pstate_init);
+static int __init intel_pstate_setup(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "disable"))
+ no_load = 1;
+ return 0;
+}
+early_param("intel_pstate", intel_pstate_setup);
+
MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
MODULE_LICENSE("GPL");