ACPI / ACPICA: Defer enabling of runtime GPEs (v3)

The current ACPI GPEs initialization code has a problem that it
enables some GPEs pointed to by device _PRW methods, generally
intended for signaling wakeup events (system or device wakeup).
These GPEs are then almost immediately disabled by the ACPI namespace
scanning code with the help of acpi_gpe_can_wake(), but it would be
better not to enable them at all until really necessary.

Modify the initialization of GPEs so that the ones that have
associated _Lxx or _Exx methods and are not pointed to by any _PRW
methods will be enabled after the namespace scan is complete.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index b23825e..f87f046 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1431,6 +1431,7 @@ EXPORT_SYMBOL(acpi_bus_add);
 int acpi_bus_start(struct acpi_device *device)
 {
 	struct acpi_bus_ops ops;
+	int result;
 
 	if (!device)
 		return -EINVAL;
@@ -1438,7 +1439,11 @@ int acpi_bus_start(struct acpi_device *device)
 	memset(&ops, 0, sizeof(ops));
 	ops.acpi_op_start = 1;
 
-	return acpi_bus_scan(device->handle, &ops, NULL);
+	result = acpi_bus_scan(device->handle, &ops, NULL);
+
+	acpi_update_gpes();
+
+	return result;
 }
 EXPORT_SYMBOL(acpi_bus_start);
 
@@ -1552,6 +1557,8 @@ int __init acpi_scan_init(void)
 
 	if (result)
 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
+	else
+		acpi_update_gpes();
 
 	return result;
 }