vb2_core_dqbuf
EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
ret = vb2_core_dqbuf(q, &index, NULL, 0);
ret = vb2_core_dqbuf(q, NULL, b, nonblocking);
ret = vb2_core_dqbuf(&ctx->vb_q, &b->index, b, ctx->nonblocking);
int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,