SPDIF_QSUB_SIZE
size = SPDIF_QSUB_SIZE;
ctrl->ready_buf = (ctrl->qpos - 1) / SPDIF_QSUB_SIZE + 1;
unsigned char qsub[2 * SPDIF_QSUB_SIZE];
uinfo->count = SPDIF_QSUB_SIZE;
int idx = (ctrl->ready_buf - 1) * SPDIF_QSUB_SIZE;
&ctrl->qsub[idx], SPDIF_QSUB_SIZE);