V4L/DVB: videobuf: Add support for V4L2_BUF_FLAG_ERROR

For recoverable stream errors dqbuf() now returns 0 and the error flag
is set instead of returning EIO.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/videobuf-core.c

@@ -285,8 +285,10 @@ static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
 	case VIDEOBUF_ACTIVE:
 		b->flags |= V4L2_BUF_FLAG_QUEUED;
 		break;
-	case VIDEOBUF_DONE:
 	case VIDEOBUF_ERROR:
+		b->flags |= V4L2_BUF_FLAG_ERROR;
+		/* fall through */
+	case VIDEOBUF_DONE:
 		b->flags |= V4L2_BUF_FLAG_DONE;
 		break;
 	case VIDEOBUF_NEEDS_INIT:
@@ -670,6 +672,7 @@ int videobuf_dqbuf(struct videobuf_queue *q,
 
 	MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
 
+	memset(b, 0, sizeof(*b));
 	mutex_lock(&q->vb_lock);
 
 	retval = stream_next_buffer(q, &buf, nonblocking);
@@ -681,23 +684,20 @@ int videobuf_dqbuf(struct videobuf_queue *q,
 	switch (buf->state) {
 	case VIDEOBUF_ERROR:
 		dprintk(1, "dqbuf: state is error\n");
-		retval = -EIO;
-		CALL(q, sync, q, buf);
-		buf->state = VIDEOBUF_IDLE;
 		break;
 	case VIDEOBUF_DONE:
 		dprintk(1, "dqbuf: state is done\n");
-		CALL(q, sync, q, buf);
-		buf->state = VIDEOBUF_IDLE;
 		break;
 	default:
 		dprintk(1, "dqbuf: state invalid\n");
 		retval = -EINVAL;
 		goto done;
 	}
-	list_del(&buf->stream);
-	memset(b, 0, sizeof(*b));
+	CALL(q, sync, q, buf);
 	videobuf_status(q, b, buf, q->type);
+	list_del(&buf->stream);
+	buf->state = VIDEOBUF_IDLE;
+	b->flags &= ~V4L2_BUF_FLAG_DONE;
 done:
 	mutex_unlock(&q->vb_lock);
 	return retval;