vb2_core_qbuf
err = vb2_core_qbuf(vb->vb2_queue, vb, NULL, NULL);
EXPORT_SYMBOL_GPL(vb2_core_qbuf);
ret = vb2_core_qbuf(q, vb2, NULL, NULL);
ret = vb2_core_qbuf(q, b, NULL, NULL);
ret = vb2_core_qbuf(q, vb, NULL, NULL);
ret = vb2_core_qbuf(q, vb, b, req);
ret = vb2_core_qbuf(&ctx->vb_q, vb2, b, NULL);
int vb2_core_qbuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb,