ACPI / scan: do not scan fixed hardware on HW-reduced platform

Commit Message

Aaron Lu April 28, 2014, 2:38 a.m. UTC

Fixed hardware does not exist on HW-reduced ACPI platform since the
programming interface for them is not implemented on those platforms,
so no need to scan them.
This patch avoids creating the fixed power button ACPI device and
eliminates a probe error message from ACPI button driver on ASUS T100.

Signed-off-by: Aaron Lu <[e-mail]>
---
 drivers/acpi/scan.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

Patch

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7efe546a8c42..db5fc6f9628e 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2259,12 +2259,16 @@  int __init acpi_scan_init(void)
 	if (result)
 		goto out;
 
-	result = acpi_bus_scan_fixed();
-	if (result) {
-		acpi_detach_data(acpi_root->handle, acpi_scan_drop_device);
-		acpi_device_del(acpi_root);
-		put_device(&acpi_root->dev);
-		goto out;
+	/* Fixed feature devices do not exist on HW-reduced platform */
+	if (!acpi_gbl_reduced_hardware) {
+		result = acpi_bus_scan_fixed();
+		if (result) {
+			acpi_detach_data(acpi_root->handle,
+					 acpi_scan_drop_device);
+			acpi_device_del(acpi_root);
+			put_device(&acpi_root->dev);
+			goto out;
+		}
 	}
 
 	acpi_update_all_gpes();