On Wednesday, August 9, 2017 12:41:15 AM CEST Srinivas Pandruvada wrote: > For SoC to achieve its lowest power platform idle state a set of hardware > preconditions must be met. These preconditions or constraints can be > obtained by issuing a device specific method (_DSM) with function "1". > Refer to the document provided in the link below. > > Here during initialization (from attach() callback of LPS0 device), invoke > function 1 to get the device constraints. Each enabled constraint is > stored in a table. > > The devices in this table are used to check whether they were in required > minimum state, while entering suspend. This check is done from platform > freeze wake() callback, only when /sys/power/pm_debug_messages attribute > is non zero. > > If any constraint is not met and device is ACPI power managed then it > prints the device name to kernel logs. > > Also if debug is enabled in acpi/sleep.c, the constraint table and state > of each device on wake is dumped in kernel logs. > > Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> > --- > drivers/acpi/sleep.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 162 insertions(+) > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > index 2b881de..b3ef577 100644 > --- a/drivers/acpi/sleep.c > +++ b/drivers/acpi/sleep.c > @@ -669,6 +669,7 @@ static const struct acpi_device_id lps0_device_ids[] = { [cut] > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > */ > if (acpi_sci_irq_valid() && > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) { > + if (pm_debug_messages_enabled()) > + lpi_check_constraints(); I'm not sure why you only want to check the constraints when we do the _cancel_wakeup() thing. IMO the check is relevant regardless of whether or not the wakeup was via ACPI. > pm_system_cancel_wakeup(); > s2idle_wakeup = true; > } > -- 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
