x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops

[pandora-kernel.git] / drivers / input / serio / i8042-x86ia64io.h

diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index cd1a843..031270c 100644 (file)
--- a/drivers/input/serio/i8042-x86ia64io.h
+++ b/drivers/input/serio/i8042-x86ia64io.h
@@ -914,6 +914,7 @@ static int __init i8042_platform_init(void)
        int retval;
 
 #ifdef CONFIG_X86
+       u8 a20_on = 0xdf;
        /* Just return if pre-detection shows no i8042 controller exist */
        if (!x86_platform.i8042_detect())
                return -ENODEV;
@@ -953,6 +954,14 @@ static int __init i8042_platform_init(void)
 
        if (dmi_check_system(i8042_dmi_dritek_table))
                i8042_dritek = true;
+
+       /*
+        * A20 was already enabled during early kernel init. But some buggy
+        * BIOSes (in MSI Laptops) require A20 to be enabled using 8042 to
+        * resume from S3. So we do it here and hope that nothing breaks.
+        */
+       i8042_command(&a20_on, 0x10d1);
+       i8042_command(NULL, 0x00ff);    /* Null command for SMM firmware */
 #endif /* CONFIG_X86 */
 
        return retval;