diff -ur x/linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.c linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.c
--- x/linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.c	2013-09-16 23:17:51.000000000 +0300
+++ linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.c	2013-09-17 19:17:02.787833512 +0300
@@ -136,6 +136,10 @@
 module_param_named(enable_ips, i915_enable_ips, int, 0600);
 MODULE_PARM_DESC(enable_ips, "Enable IPS (default: true)");
 
+bool i915_ignore_edp_bpp __read_mostly;
+module_param_named(i915_ignore_edp_bpp, i915_ignore_edp_bpp, bool, 0600);
+MODULE_PARM_DESC(i915_ignore_edp_bpp, "Ignore BDB edp BPP value (default: false)");
+
 bool i915_fastboot __read_mostly = 0;
 module_param_named(fastboot, i915_fastboot, bool, 0600);
 MODULE_PARM_DESC(fastboot, "Try to skip unnecessary mode sets at boot time "
diff -ur x/linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.h linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.h
--- x/linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.h	2013-09-16 23:17:51.000000000 +0300
+++ linux-3.12-rc1/drivers/gpu/drm/i915/i915_drv.h	2013-09-17 16:50:41.971598369 +0300
@@ -651,6 +651,7 @@
 #define QUIRK_LVDS_SSC_DISABLE (1<<1)
 #define QUIRK_INVERT_BRIGHTNESS (1<<2)
 #define QUIRK_NO_PCH_PWM_ENABLE (1<<3)
+#define QUIRK_IGNORE_EDP_BPP (1<<4)
 
 struct intel_fbdev;
 struct intel_fbc_work;
@@ -1713,6 +1714,7 @@
 extern unsigned int i915_preliminary_hw_support __read_mostly;
 extern int i915_disable_power_well __read_mostly;
 extern int i915_enable_ips __read_mostly;
+extern bool i915_ignore_edp_bpp __read_mostly;
 extern bool i915_fastboot __read_mostly;
 extern int i915_enable_pc8 __read_mostly;
 extern int i915_pc8_timeout __read_mostly;
diff -ur x/linux-3.12-rc1/drivers/gpu/drm/i915/intel_display.c linux-3.12-rc1/drivers/gpu/drm/i915/intel_display.c
--- x/linux-3.12-rc1/drivers/gpu/drm/i915/intel_display.c	2013-09-16 23:17:51.000000000 +0300
+++ linux-3.12-rc1/drivers/gpu/drm/i915/intel_display.c	2013-09-17 16:50:30.463598061 +0300
@@ -9932,6 +9932,17 @@
 	DRM_INFO("applying no-PCH_PWM_ENABLE quirk\n");
 }
 
+/*
+ * Some machines (e.g. Asus TX300) incorrectly return 18bpp in UEFI mode
+ * from vbe edp data
+ */
+static void quirk_no_edp_bpp_enable(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	dev_priv->quirks |= QUIRK_IGNORE_EDP_BPP;
+	DRM_INFO("applying IGNORE_EDP_BPP quirk\n");
+}
+
 struct intel_quirk {
 	int device;
 	int subsystem_vendor;
@@ -10006,6 +10017,11 @@
 	{ 0x0116, 0x1028, 0x052e, quirk_no_pcm_pwm_enable },
 	/* Dell XPS13 HD and XPS13 FHD Ivy Bridge */
 	{ 0x0166, 0x1028, 0x058b, quirk_no_pcm_pwm_enable },
+
+	/* at least Asus TX300 (0x1042 0x15b7),
+	   UX32VD (0x1042 0x1507), Dell XPS13 and Toshiba Kirabook,
+	   see https://bugzilla.kernel.org/show_bug.cgi?id=59841 */
+	{ 0x0166, PCI_ANY_ID, PCI_ANY_ID, quirk_no_edp_bpp_enable },
 };
 
 static void intel_init_quirks(struct drm_device *dev)
diff -ur x/linux-3.12-rc1/drivers/gpu/drm/i915/intel_dp.c linux-3.12-rc1/drivers/gpu/drm/i915/intel_dp.c
--- x/linux-3.12-rc1/drivers/gpu/drm/i915/intel_dp.c	2013-09-16 23:17:51.000000000 +0300
+++ linux-3.12-rc1/drivers/gpu/drm/i915/intel_dp.c	2013-09-17 16:50:41.975598369 +0300
@@ -731,7 +731,9 @@
 	/* Walk through all bpp values. Luckily they're all nicely spaced with 2
 	 * bpc in between. */
 	bpp = pipe_config->pipe_bpp;
-	if (is_edp(intel_dp) && dev_priv->vbt.edp_bpp) {
+	if (is_edp(intel_dp) && dev_priv->vbt.edp_bpp
+	    && !i915_ignore_edp_bpp
+	    && !(dev_priv->quirks & QUIRK_IGNORE_EDP_BPP)) {
 		DRM_DEBUG_KMS("clamping bpp for eDP panel to BIOS-provided %i\n",
 			      dev_priv->vbt.edp_bpp);
 		bpp = min_t(int, bpp, dev_priv->vbt.edp_bpp);