ACPI: EC: Enable boot EC before bus_scan

Some _STA methods called during bus_scan() might require EC region handler,
which might be enabled later in the scan.
Enable it explicitly before scan to avoid errors.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9627

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 5b4d462117cf..cbfe9ae7a9e5 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1449,6 +1449,8 @@ static int acpi_bus_scan_fixed(struct acpi_device *root)
         return result;
 }
 
+int __init acpi_boot_ec_enable(void);
+
 static int __init acpi_scan_init(void)
 {
         int result;
@@ -1480,6 +1482,10 @@ static int __init acpi_scan_init(void)
          * Enumerate devices in the ACPI namespace.
          */
         result = acpi_bus_scan_fixed(acpi_root);
+
+        /* EC region might be needed at bus_scan, so enable it now */
+        acpi_boot_ec_enable();
+
         if (!result)
                 result = acpi_bus_scan(acpi_root, &ops);