[PATCH 6/6] ACPI: EC: Use fast path in acpi_ec_add() for DSDT boot EC

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

If the boot EC comes from the DSDT, its ACPI handle is equal to the
handle of a device object with the PNP0C09 device ID.  If that
device object is passed to acpi_ec_add(), it is not necessary to
allocate a new EC structure for it and parse it, because that has
been done already, so change the function to use the fast path in
that case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/ec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 4ed0c6155d3f..920a08c01ab6 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1614,7 +1614,8 @@ static int acpi_ec_add(struct acpi_device *device)
 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 
-	if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
+	if ((boot_ec && boot_ec->handle == device->handle) ||
+	    !strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
 		/* Fast path: this device corresponds to the boot EC. */
 		ec = boot_ec;
 	} else {
-- 
2.16.4