Fix a win7 compability issue on Asus K50IJ.
Here is the _BCM method of this laptop:
                    Method (_BCM, 1, NotSerialized)
                    {
                        If (LGreaterEqual (OSFG, OSVT))
                        {
                            If (LNotEqual (OSFG, OSW7))
                            {
                                Store (One, BCMD)
                                Store (GCBL (Arg0), Local0)
                                Subtract (0x0F, Local0, LBTN)
                                ^^^SBRG.EC0.STBR ()
                                ...
                            }
                            Else
                            {
                                DBGR (0x0B, Zero, Zero, Arg0)
                                Store (Arg0, LBTN)
                                ^^^SBRG.EC0.STBR ()
                                ...
                            }
                        }
                    }
LBTN is used to store the index of the brightness level in the _BCL.
GCBL is a method that convert the percentage value to the index value.
If _OSI(Windows 2009) is not disabled, LBTN is stored a percentage
value which is surely beyond the end of _BCL package.
http://bugzilla.kernel.org/show_bug.cgi?id=14753
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
        acpi_osi_setup("!Windows 2006");
        return 0;
 }
+static int __init dmi_disable_osi_win7(const struct dmi_system_id *d)
+{
+       printk(KERN_NOTICE PREFIX "DMI detected: %s\n", d->ident);
+       acpi_osi_setup("!Windows 2009");
+       return 0;
+}
 
 static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
        {
                     DMI_MATCH(DMI_PRODUCT_NAME, "Sony VGN-SR290J"),
                },
        },
+       {
+       .callback = dmi_disable_osi_win7,
+       .ident = "ASUS K50IJ",
+       .matches = {
+                    DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
+                    DMI_MATCH(DMI_PRODUCT_NAME, "K50IJ"),
+               },
+       },
 
        /*
         * BIOS invocation of _OSI(Linux) is almost always a BIOS bug.