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 fccd361f7b5..87aa5f5d3c8 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 69a2b16f42a..d4ab3beaada 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 dc095526ffb..142fee5f983 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;