diff --git a/common/hw-gfx-gma-config_helpers.adb b/common/hw-gfx-gma-config_helpers.adb
index f2b4ef6..5e5be5d 100644
--- a/common/hw-gfx-gma-config_helpers.adb
+++ b/common/hw-gfx-gma-config_helpers.adb
@@ -181,9 +181,9 @@
    -- Validates that a given configuration should work with
    -- a given framebuffer.
    function Validate_Config
-     (FB       : Framebuffer_Type;
-      Port_Cfg : Port_Config;
-      Pipe     : Pipe_Index)
+     (FB    : Framebuffer_Type;
+      Mode  : Mode_Type;
+      Pipe  : Pipe_Index)
       return Boolean
    is
    begin
@@ -197,11 +197,11 @@
       -- Plane_Control)
       -- 90 degree rotations are only supported with Y-tiling
       return
-         ((Rotated_Width (FB) = Port_Cfg.Mode.H_Visible and
-           Rotated_Height (FB) = Port_Cfg.Mode.V_Visible) or
+         ((Rotated_Width (FB) = Mode.H_Visible and
+           Rotated_Height (FB) = Mode.V_Visible) or
           (Rotated_Width (FB) <= Config.Maximum_Scalable_Width (Pipe) and
-           Rotated_Width (FB) <= Port_Cfg.Mode.H_Visible and
-           Rotated_Height (FB) <= Port_Cfg.Mode.V_Visible)) and
+           Rotated_Width (FB) <= Mode.H_Visible and
+           Rotated_Height (FB) <= Mode.V_Visible)) and
          (FB.Offset /= VGA_PLANE_FRAMEBUFFER_OFFSET or Pipe = Primary) and
          (FB.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
           (FB.BPC = 8 and Valid_Stride (FB) and