diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5fdf714f40a067a02b35b41c1e56117b4854c72c..d006bb22f3cac5fd6d6b47f6a4c5a675beedef03 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1446,6 +1446,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. disable Do not enable intel_pstate as the default scaling driver for the supported processors + force + Enable intel_pstate on systems that prohibit it by default + in favor of acpi-cpufreq. Forcing the intel_pstate driver + instead of acpi-cpufreq may disable platform features, such + as thermal controls and power capping, that rely on ACPI + P-States information being indicated to OSPM and therefore + should be used with caution. This option does not work with + processors that aren't supported by the intel_pstate driver + or on platforms that use pcc-cpufreq instead of acpi-cpufreq. no_hwp Do not enable hardware P state control (HWP) if available. diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 1405b393c93d90f68ac77f3ba9e23e223bcb80a3..0e841eecb74336f2f0d5d6b98f47874163ca4c6c 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -948,6 +948,7 @@ static struct cpufreq_driver intel_pstate_driver = { static int __initdata no_load; static int __initdata no_hwp; +static unsigned int force_load; static int intel_pstate_msrs_not_valid(void) { @@ -1094,7 +1095,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void) case PSS: return intel_pstate_no_acpi_pss(); case PPC: - return intel_pstate_has_acpi_ppc(); + return intel_pstate_has_acpi_ppc() && + (!force_load); } } @@ -1175,6 +1177,8 @@ static int __init intel_pstate_setup(char *str) no_load = 1; if (!strcmp(str, "no_hwp")) no_hwp = 1; + if (!strcmp(str, "force")) + force_load = 1; return 0; } early_param("intel_pstate", intel_pstate_setup);