[media] usbtv: Throw corrupted frames away

Ignore out of order data and mark incomplete buffers as errored.
This gets rid of annoying flicker due to occassional garbage from hardware.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: stable@vger.kernel.org

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/media/usb/usbtv/usbtv.c b/drivers/media/usb/usbtv/usbtv.c
index 55a45d34df22..8a505a90d318 100644
--- a/drivers/media/usb/usbtv/usbtv.c
+++ b/drivers/media/usb/usbtv/usbtv.c
@@ -88,6 +88,7 @@ struct usbtv {
         /* Number of currently processed frame, useful find
          * out when a new one begins. */
         u32 frame_id;
+        int chunks_done;
 
         enum {
                 USBTV_COMPOSITE_INPUT,
@@ -299,8 +300,13 @@ static void usbtv_image_chunk(struct usbtv *usbtv, u32 *chunk)
                 return;
 
         /* Beginning of a frame. */
-        if (chunk_no == 0)
+        if (chunk_no == 0) {
                 usbtv->frame_id = frame_id;
+                usbtv->chunks_done = 0;
+        }
+
+        if (usbtv->frame_id != frame_id)
+                return;
 
         spin_lock_irqsave(&usbtv->buflock, flags);
         if (list_empty(&usbtv->bufs)) {
@@ -315,16 +321,21 @@ static void usbtv_image_chunk(struct usbtv *usbtv, u32 *chunk)
 
         /* Copy the chunk data. */
         usbtv_chunk_to_vbuf(frame, &chunk[1], chunk_no, odd);
+        usbtv->chunks_done++;
 
         /* Last chunk in a frame, signalling an end */
         if (odd && chunk_no == USBTV_CHUNKS-1) {
                 int size = vb2_plane_size(&buf->vb, 0);
+                enum vb2_buffer_state state = usbtv->chunks_done ==
+                                                USBTV_CHUNKS ?
+                                                VB2_BUF_STATE_DONE :
+                                                VB2_BUF_STATE_ERROR;
 
                 buf->vb.v4l2_buf.field = V4L2_FIELD_INTERLACED;
                 buf->vb.v4l2_buf.sequence = usbtv->sequence++;
                 v4l2_get_timestamp(&buf->vb.v4l2_buf.timestamp);
                 vb2_set_plane_payload(&buf->vb, 0, size);
-                vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
+                vb2_buffer_done(&buf->vb, state);
                 list_del(&buf->list);
         }