static bool
 intel_dp_adjust_dithering(struct intel_dp *intel_dp,
                          struct drm_display_mode *mode,
-                         struct drm_display_mode *adjusted_mode)
+                         bool adjust_mode)
 {
        int max_link_clock = intel_dp_link_clock(intel_dp_max_link_bw(intel_dp));
        int max_lanes = intel_dp_max_lane_count(intel_dp);
                if (mode_rate > max_rate)
                        return false;
 
-               if (adjusted_mode)
-                       adjusted_mode->private_flags
+               if (adjust_mode)
+                       mode->private_flags
                                |= INTEL_MODE_DP_FORCE_6BPC;
 
                return true;
                        return MODE_PANEL;
        }
 
-       if (!intel_dp_adjust_dithering(intel_dp, mode, NULL))
+       if (!intel_dp_adjust_dithering(intel_dp, mode, false))
                return MODE_CLOCK_HIGH;
 
        if (mode->clock < 10000)
                                        mode, adjusted_mode);
        }
 
-       if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+       if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK)
                return false;
 
        DRM_DEBUG_KMS("DP link computation with max lane count %i "
                      "max bw %02x pixel clock %iKHz\n",
                      max_lane_count, bws[max_clock], adjusted_mode->clock);
 
-       if (!intel_dp_adjust_dithering(intel_dp, adjusted_mode, adjusted_mode))
+       if (!intel_dp_adjust_dithering(intel_dp, adjusted_mode, true))
                return false;
 
        bpp = adjusted_mode->private_flags & INTEL_MODE_DP_FORCE_6BPC ? 18 : 24;
 
                                   struct drm_display_mode *adjusted_mode);
 extern void intel_pch_panel_fitting(struct drm_device *dev,
                                    int fitting_mode,
-                                   struct drm_display_mode *mode,
+                                   const struct drm_display_mode *mode,
                                    struct drm_display_mode *adjusted_mode);
 extern u32 intel_panel_get_max_backlight(struct drm_device *dev);
 extern u32 intel_panel_get_backlight(struct drm_device *dev);
 
 void
 intel_pch_panel_fitting(struct drm_device *dev,
                        int fitting_mode,
-                       struct drm_display_mode *mode,
+                       const struct drm_display_mode *mode,
                        struct drm_display_mode *adjusted_mode)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;