int udl_render_hline(struct drm_device *dev, int bpp, struct urb **urb_ptr,
                     const char *front, char **urb_buf_ptr,
-                    u32 byte_offset, u32 byte_width,
+                    u32 byte_offset, u32 device_byte_offset, u32 byte_width,
                     int *ident_ptr, int *sent_ptr);
 
 int udl_dumb_create(struct drm_file *file_priv,
 
        list_for_each_entry(cur, &fbdefio->pagelist, lru) {
 
                if (udl_render_hline(dev, (ufbdev->ufb.base.bits_per_pixel / 8),
-                                 &urb, (char *) info->fix.smem_start,
-                                 &cmd, cur->index << PAGE_SHIFT,
-                                 PAGE_SIZE, &bytes_identical, &bytes_sent))
+                                    &urb, (char *) info->fix.smem_start,
+                                    &cmd, cur->index << PAGE_SHIFT,
+                                    cur->index << PAGE_SHIFT,
+                                    PAGE_SIZE, &bytes_identical, &bytes_sent))
                        goto error;
                bytes_rendered += PAGE_SIZE;
        }
        for (i = y; i < y + height ; i++) {
                const int line_offset = fb->base.pitches[0] * i;
                const int byte_offset = line_offset + (x * bpp);
-
+               const int dev_byte_offset = (fb->base.width * bpp * i) + (x * bpp);
                if (udl_render_hline(dev, bpp, &urb,
                                     (char *) fb->obj->vmapping,
-                                    &cmd, byte_offset, width * bpp,
+                                    &cmd, byte_offset, dev_byte_offset,
+                                    width * bpp,
                                     &bytes_identical, &bytes_sent))
                        goto error;
        }
 
  */
 int udl_render_hline(struct drm_device *dev, int bpp, struct urb **urb_ptr,
                     const char *front, char **urb_buf_ptr,
-                    u32 byte_offset, u32 byte_width,
+                    u32 byte_offset, u32 device_byte_offset,
+                    u32 byte_width,
                     int *ident_ptr, int *sent_ptr)
 {
        const u8 *line_start, *line_end, *next_pixel;
-       u32 base16 = 0 + (byte_offset / bpp) * 2;
+       u32 base16 = 0 + (device_byte_offset / bpp) * 2;
        struct urb *urb = *urb_ptr;
        u8 *cmd = *urb_buf_ptr;
        u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;