diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 0ed6baff4b0c2146d133006c52542b48076c5cc4..56846ed5ee55b1b4686afb4a2fb56a359f80c9bf 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -499,12 +499,8 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 
 	edp = find_section(bdb, BDB_EDP);
 	if (!edp) {
-		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support) {
-			DRM_DEBUG_KMS("No eDP BDB found but eDP panel "
-				      "supported, assume %dbpp panel color "
-				      "depth.\n",
-				      dev_priv->edp.bpp);
-		}
+		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support)
+			DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported.\n");
 		return;
 	}
 
@@ -657,9 +653,6 @@ init_vbt_defaults(struct drm_i915_private *dev_priv)
 	dev_priv->lvds_use_ssc = 1;
 	dev_priv->lvds_ssc_freq = intel_bios_ssc_frequency(dev, 1);
 	DRM_DEBUG_KMS("Set default to SSC at %dMHz\n", dev_priv->lvds_ssc_freq);
-
-	/* eDP data */
-	dev_priv->edp.bpp = 18;
 }
 
 static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4154bcd7a0708b957d4b176607662933ac49fc0d..b426d44a2b055d5a8afb31a0ba4bc9fd40ea0554 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3845,7 +3845,7 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
 			/* Use VBT settings if we have an eDP panel */
 			unsigned int edp_bpc = dev_priv->edp.bpp / 3;
 
-			if (edp_bpc < display_bpc) {
+			if (edp_bpc && edp_bpc < display_bpc) {
 				DRM_DEBUG_KMS("clamping display bpc (was %d) to eDP (%d)\n", display_bpc, edp_bpc);
 				display_bpc = edp_bpc;
 			}
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 72f41aaa71ff330637bdc82d4ee8e0c04091bdf2..442968f8b20151e16d4b8bbd6e15093fb4d7ed85 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2373,15 +2373,9 @@ int intel_enable_rc6(const struct drm_device *dev)
 	if (i915_enable_rc6 >= 0)
 		return i915_enable_rc6;
 
-	if (INTEL_INFO(dev)->gen == 5) {
-#ifdef CONFIG_INTEL_IOMMU
-		/* Disable rc6 on ilk if VT-d is on. */
-		if (intel_iommu_gfx_mapped)
-			return false;
-#endif
-		DRM_DEBUG_DRIVER("Ironlake: only RC6 available\n");
-		return INTEL_RC6_ENABLE;
-	}
+	/* Disable RC6 on Ironlake */
+	if (INTEL_INFO(dev)->gen == 5)
+		return 0;
 
 	if (IS_HASWELL(dev)) {
 		DRM_DEBUG_DRIVER("Haswell: only RC6 available\n");
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index c600fb06e25e6a4798cd7f7f5841593025d3f484..a6ac0b416964c3751475522654cac0ccb6ccc574 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -2201,7 +2201,6 @@ intel_sdvo_dvi_init(struct intel_sdvo *intel_sdvo, int device)
 		connector->connector_type = DRM_MODE_CONNECTOR_HDMIA;
 		intel_sdvo->is_hdmi = true;
 	}
-	intel_sdvo->base.cloneable = true;
 
 	intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
 	if (intel_sdvo->is_hdmi)
@@ -2232,7 +2231,6 @@ intel_sdvo_tv_init(struct intel_sdvo *intel_sdvo, int type)
 
 	intel_sdvo->is_tv = true;
 	intel_sdvo->base.needs_tv_clock = true;
-	intel_sdvo->base.cloneable = false;
 
 	intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
 
@@ -2275,8 +2273,6 @@ intel_sdvo_analog_init(struct intel_sdvo *intel_sdvo, int device)
 		intel_sdvo_connector->output_flag = SDVO_OUTPUT_RGB1;
 	}
 
-	intel_sdvo->base.cloneable = true;
-
 	intel_sdvo_connector_init(intel_sdvo_connector,
 				  intel_sdvo);
 	return true;
@@ -2307,9 +2303,6 @@ intel_sdvo_lvds_init(struct intel_sdvo *intel_sdvo, int device)
 		intel_sdvo_connector->output_flag = SDVO_OUTPUT_LVDS1;
 	}
 
-	/* SDVO LVDS is not cloneable because the input mode gets adjusted by the encoder */
-	intel_sdvo->base.cloneable = false;
-
 	intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
 	if (!intel_sdvo_create_enhance_property(intel_sdvo, intel_sdvo_connector))
 		goto err;
@@ -2721,6 +2714,16 @@ bool intel_sdvo_init(struct drm_device *dev, uint32_t sdvo_reg, bool is_sdvob)
 		goto err_output;
 	}
 
+	/*
+	 * Cloning SDVO with anything is often impossible, since the SDVO
+	 * encoder can request a special input timing mode. And even if that's
+	 * not the case we have evidence that cloning a plain unscaled mode with
+	 * VGA doesn't really work. Furthermore the cloning flags are way too
+	 * simplistic anyway to express such constraints, so just give up on
+	 * cloning for SDVO encoders.
+	 */
+	intel_sdvo->base.cloneable = false;
+
 	/* Only enable the hotplug irq if we need it, to work around noisy
 	 * hotplug lines.
 	 */