diff --git a/arch/x86/kernel/acpi/processor.c b/arch/x86/kernel/acpi/processor.c index de2d2e4ebad9..7c074eec39fb 100644 --- a/arch/x86/kernel/acpi/processor.c +++ b/arch/x86/kernel/acpi/processor.c @@ -56,6 +56,12 @@ static void init_intel_pdc(struct acpi_processor *pr, struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_ACPI)) buf[2] |= ACPI_PDC_T_FFH; + /* + * If mwait/monitor is unsupported, C2/C3_FFH will be disabled + */ + if (!cpu_has(c, X86_FEATURE_MWAIT)) + buf[2] &= ~(ACPI_PDC_C_C2C3_FFH); + obj->type = ACPI_TYPE_BUFFER; obj->buffer.length = 12; obj->buffer.pointer = (u8 *) buf;