applied. thanks, -Len On Tue, 17 Jun 2008, Zhao Yakui wrote: > Subject: ACPI: Disable the C2C3_FFH access mode if MWAIT is unsupported > From: Zhao Yakui <yakui.zhao@xxxxxxxxx> > > After the following commit is merged, C2C3_FFH mode will be enabled and > passed into the _PDC object. If the BIOS thinks that MWAIT is supported and > the CPU doesn't support MWAIT, the incorrect power states will be returned > by the _CST object. So it will be better to disable C2C3_FFH access mode > if MWAIT is unsupported. > > commit 991528d7348667924176f3e29addea0675298944 > Author: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx> > Date: Mon Sep 25 16:28:13 2006 -0700 > > ACPI: Processor native C-states using MWAIT > > Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx> > Signed-off-by: Li Shaohua <shaohua.li@xxxxxxxxx> > --- > arch/x86/kernel/acpi/processor.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > Index: linux-2.6/arch/x86/kernel/acpi/processor.c > =================================================================== > --- linux-2.6.orig/arch/x86/kernel/acpi/processor.c > +++ linux-2.6/arch/x86/kernel/acpi/processor.c > @@ -61,6 +61,12 @@ static void init_intel_pdc(struct acpi_p > 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; > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
