RCB_RING_PREFETCH_EN_REG
dsaf_write_dev(q, RCB_RING_PREFETCH_EN_REG, 0);
regs[20] = dsaf_read_dev(queue, RCB_RING_PREFETCH_EN_REG);
dsaf_write_dev(q, RCB_RING_PREFETCH_EN_REG, !!val);