NAK. Dell told me they disabled C3 on this box on purpose. If there is a measurable power saving case to over-ride Dell and no sign of a stability issue, please re-open bugzilla 8703. thanks, -len On Mon, 9 Jun 2008, akpm@xxxxxxxxxxxxxxxxxxxx wrote: > From: Dag Bakke <dag@xxxxxxxxx> > > Taken from http://bugzilla.kernel.org/show_bug.cgi?id=8703 > > [akpm@xxxxxxxxxxxxxxxxxxxx: fix warning] > Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx> > Cc: Len Brown <lenb@xxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > drivers/acpi/processor_idle.c | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > diff -puN drivers/acpi/processor_idle.c~acpi-enable-c3-power-state-on-dell-inspiron-8200 drivers/acpi/processor_idle.c > --- a/drivers/acpi/processor_idle.c~acpi-enable-c3-power-state-on-dell-inspiron-8200 > +++ a/drivers/acpi/processor_idle.c > @@ -103,6 +103,8 @@ static unsigned int latency_factor __rea > module_param(latency_factor, uint, 0644); > #endif > > +static int forced_c3; > + > /* > * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. > * For now disable this. Probably a bug somewhere else. > @@ -123,6 +125,19 @@ static int set_max_cstate(const struct d > return 0; > } > > +/* > + * Some (Dell) machines set the C3 latency to a value which effectively says: > + * "Don't use C3." Still, C3 works if we force it. > + * This enables C3 on Dell Inspiron 8200 machines. > + */ > +static int dmi_force_c3(const struct dmi_system_id *id) > +{ > + forced_c3 = 1; > + printk(KERN_NOTICE PREFIX "%s detected - Force enabling C3.", > + id->ident); > + return 0; > +} > + > /* Actually this shouldn't be __cpuinitdata, would be better to fix the > callers to only run once -AK */ > static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = { > @@ -181,6 +196,9 @@ static struct dmi_system_id __cpuinitdat > DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), > DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, > (void *)2}, > + { dmi_force_c3, "Dell Inspiron 8200", { > + DMI_MATCH(DMI_SYS_VENDOR,"Dell Computer Corporation"), > + DMI_MATCH(DMI_PRODUCT_NAME,"Inspiron 8200") }, NULL}, > {}, > }; > > @@ -1050,11 +1068,12 @@ static void acpi_processor_power_verify_ > * C3 latency must be less than or equal to 1000 > * microseconds. > */ > - else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { > + if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY && !forced_c3) { > ACPI_DEBUG_PRINT((ACPI_DB_INFO, > "latency too large [%d]\n", cx->latency)); > return; > - } > + } else if (forced_c3) > + cx->latency = ACPI_PROCESSOR_MAX_C3_LATENCY; > > /* > * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) > _ > -- 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
