3 files changed, 11 insertions, 8 deletions

diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
index fccd361f7b50..87aa5f5d3c88 100644
--- a/drivers/gpu/drm/udl/udl_drv.h
+++ b/drivers/gpu/drm/udl/udl_drv.h
@@ -104,7 +104,7 @@ udl_fb_user_fb_create(struct drm_device *dev,
 
 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,
diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index 69a2b16f42a6..d4ab3beaada0 100644
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -114,9 +114,10 @@ static void udlfb_dpy_deferred_io(struct fb_info *info,
         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;
         }
@@ -187,10 +188,11 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
         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;
         }
diff --git a/drivers/gpu/drm/udl/udl_transfer.c b/drivers/gpu/drm/udl/udl_transfer.c
index dc095526ffb7..142fee5f983f 100644
--- a/drivers/gpu/drm/udl/udl_transfer.c
+++ b/drivers/gpu/drm/udl/udl_transfer.c
@@ -213,11 +213,12 @@ static void udl_compress_hline16(
  */
 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;