RCB_FLAG_RING_DISABLED
brp->hw_rcb.flags = nslots > 0 ? 0 : RCB_FLAG_RING_DISABLED;
rrp->hw_rcb.flags = nslots > 0 ? 0 : RCB_FLAG_RING_DISABLED;
srp->hw_rcb.flags = nslots > 0 ? 0 : RCB_FLAG_RING_DISABLED;