Xfbdev: Force shadowfb for frame buffers with non-packed pixels

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Keith Packard <keithp@keithp.com>

hw/kdrive/fbdev/fbdev.c

@@ -326,7 +326,8 @@ fbdevMapFramebuffer(KdScreenInfo * screen)
     KdPointerMatrix m;
     FbdevPriv *priv = screen->card->driver;
 
-    if (scrpriv->randr != RR_Rotate_0)
+    if (scrpriv->randr != RR_Rotate_0 ||
+        priv->fix.type != FB_TYPE_PACKED_PIXELS)
         scrpriv->shadow = TRUE;
     else
         scrpriv->shadow = FALSE;