[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>

diff --git a/drivers/media/usb/usbtv/usbtv.c b/drivers/media/usb/usbtv/usbtv.c
index 9dcc677f3015c5a44bbfdcd66f20d5fbd71578fc..91650173941ad5629a56cae9bacff0a4072002f1 100644 (file)
--- a/drivers/media/usb/usbtv/usbtv.c
+++ b/drivers/media/usb/usbtv/usbtv.c
@@ -89,6 +89,7 @@ struct usbtv {
        /* Number of currently processed frame, useful find
         * out when a new one begins. */
        u32 frame_id;
+       int chunks_done;
 
        int iso_size;
        unsigned int sequence;
@@ -242,8 +243,13 @@ 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)) {
@@ -258,16 +264,21 @@ 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);
        }