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author | Len Brown <len.brown@intel.com> | 2017-03-01 00:44:16 +0300 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-03-06 02:05:31 +0300 |
commit | d82f26925599cae83c38d17d07ae982356e81318 (patch) | |
tree | 3ee139fb6287426538053878a874a0231f51821a | |
parent | 6407829901f074cf6beef566d6af9a0b0e238f0d (diff) | |
download | linux-d82f26925599cae83c38d17d07ae982356e81318.tar.xz |
cpufreq: Add the "cpufreq.off=1" cmdline option
Add the "cpufreq.off=1" cmdline option.
At boot-time, this allows a user to request CONFIG_CPU_FREQ=n
behavior from a kernel built with CONFIG_CPU_FREQ=y.
This is analogous to the existing "cpuidle.off=1" option
and CONFIG_CPU_IDLE=y
This capability is valuable when we need to debug end-user
issues in the BIOS or in Linux. It is also convenient
for enabling comparisons, which may otherwise require a new kernel,
or help from BIOS SETUP, which may be buggy or unavailable.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 3 | ||||
-rw-r--r-- | drivers/cpufreq/cpufreq.c | 1 |
2 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index be7c0d9506b1..3988d2311f97 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -662,6 +662,9 @@ cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system + cpufreq.off=1 [CPU_FREQ] + disable the cpufreq sub-system + cpu_init_udelay=N [X86] Delay for N microsec between assert and de-assert of APIC INIT to start processors. This delay occurs diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 80a785ad17e8..7790db2645d7 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2532,4 +2532,5 @@ static int __init cpufreq_core_init(void) return 0; } +module_param(off, int, 0444); core_initcall(cpufreq_core_init); |