ACPI/PM: specify lowest allowed state for device sleep state

Lower device sleep state can save more power, but has more exit
latency too.  Sometimes, to satisfy some power QoS and other
requirement, we need to constrain the lowest device sleep state.

In this patch, a parameter to specify lowest allowed state for
acpi_pm_device_sleep_state is added.  So that the caller can enforce
the constraint via the parameter.

This is needed by PCIe D3cold support, where the lowest power state
allowed may be D3_HOT instead of default D3_COLD.

CC: Len Brown <lenb@kernel.org>
CC: linux-acpi@vger.kernel.org
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index d21e8f59c84e..507a8e2b9a4c 100644
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -170,8 +170,8 @@ static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state)
         }
 
         if (acpi_bus_power_manageable(handle)) {
-                int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL);
-
+                int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL,
+                                                             ACPI_STATE_D3);
                 if (power_state < 0)
                         power_state = (state.event == PM_EVENT_ON) ?
                                         ACPI_STATE_D0 : ACPI_STATE_D3;