PI_CMD_REQ_K_NUM_ENTRIES
bp->cmd_req_reg.index.prod &= PI_CMD_REQ_K_NUM_ENTRIES-1;
bp->cmd_req_reg.index.comp &= PI_CMD_REQ_K_NUM_ENTRIES-1;
PI_XMT_DESCR cmd_req[PI_CMD_REQ_K_NUM_ENTRIES];