diff -uNr linux-3.8.4-vanilla/drivers/acpi/blacklist.c linux-3.8.4/drivers/acpi/blacklist.c
--- linux-3.8.4-vanilla/drivers/acpi/blacklist.c   2013-03-27 01:59:55.252053268 -0400
+++ linux-3.8.4/drivers/acpi/blacklist.c   2013-03-27 02:02:19.312720822 -0400
@@ -193,6 +193,13 @@
    return 0;
 }
 
+static int __init dmi_disable_osi_win8(const struct dmi_system_id *d)
+{
+   printk(KERN_NOTICE PREFIX "DMI detected: %s\n", d->ident);
+   acpi_osi_setup("!Windows 2012");
+   return 0;
+}
+
 static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
    {
    .callback = dmi_disable_osi_vista,
@@ -268,6 +275,37 @@
       },
    },
 
+   /*
+    * The following Lenovo models have a broken workaround in the
+    * acpi_video backlight implementation to meet the Windows 8
+    * requirement of 101 backlight levels. Reverting to pre-Win8
+    * behavoir fixes the problem.
+    */
+        {
+        .callback = dmi_disable_osi_win8,
+        .ident = "Lenovo ThinkPad T430",
+        .matches = {
+                     DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+                     DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T430"),
+                },
+        },
+   {
+   .callback = dmi_disable_osi_win8,
+   .ident = "Lenovo ThinkPad T430s",
+   .matches = {
+           DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+           DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T430s"),
+      },
+   },
+   {
+   .callback = dmi_disable_osi_win8,
+   .ident = "Lenovo ThinkPad X230",
+   .matches = {
+           DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+           DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X230"),
+      },
+   },
+
    /*
     * BIOS invocation of _OSI(Linux) is almost always a BIOS bug.
     * Linux ignores it, except for the machines enumerated below.