From d82f26925599cae83c38d17d07ae982356e81318 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Tue, 28 Feb 2017 16:44:16 -0500 Subject: [PATCH] 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 Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ drivers/cpufreq/cpufreq.c | 1 + 2 files changed, 4 insertions(+) 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); -- 2.20.1