ACPI: Introduce ACPI D3_COLD state support

If a device has _PR3, it means the device supports D3_COLD.
Add the ability to validate and enter D3_COLD state in ACPI.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 8ab80bafe3f1..571396cf6110 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -885,6 +885,13 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
                                 acpi_bus_add_power_resource(ps->resources.handles[j]);
                 }
 
+                /* The exist of _PR3 indicates D3Cold support */
+                if (i == ACPI_STATE_D3) {
+                        status = acpi_get_handle(device->handle, object_name, &handle);
+                        if (ACPI_SUCCESS(status))
+                                device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
+                }
+
                 /* Evaluate "_PSx" to see if we can do explicit sets */
                 object_name[2] = 'S';
                 status = acpi_get_handle(device->handle, object_name, &handle);