DBG(0x40, "hdlc_fill_fifo");
 
-       if (skb->len == 0)
-               BUG();
+       BUG_ON(skb->len == 0);
 
        bcs->ctrl.sr.cmd &= ~HDLC_CMD_XME;
        if (bcs->tx_skb->len > bcs->fifo_size) {
 
        switch (pr) {
        case PH_DATA | REQUEST:
-               if (bcs->tx_skb)
-                       BUG();
-               
+               BUG_ON(bcs->tx_skb);
                bcs->tx_skb = skb;
                DBG_SKB(1, skb);
                hdlc_fill_fifo(bcs);
 
        unsigned char cmd;
        u_char *ptr;
 
-       if (!isac->tx_skb)
-               BUG();
+       BUG_ON(!isac->tx_skb);
 
        count = isac->tx_skb->len;
-       if (count <= 0)
-               BUG();
+       BUG_ON(count <= 0);
 
        DBG(DBG_IRQ, "count %d", count);
 
                        dev_kfree_skb(skb);
                        break;
                }
-               if (isac->tx_skb)
-                       BUG();
+               BUG_ON(isac->tx_skb);
 
                isac->tx_skb = skb;
                isac_fill_fifo(isac);
 
 
        switch (pr) {
        case PH_DATA | REQUEST:
-               if (bcs->b_out.tx_skb)
-                       BUG();
-               
+               BUG_ON(bcs->b_out.tx_skb);
                bcs->b_out.tx_skb = skb;
                break;
        case PH_ACTIVATE | REQUEST:
 
                break;
        case PH_DATA | REQUEST:
                DBG(2, "PH_DATA REQUEST len %d", skb->len);
-               if (adapter->d_out.tx_skb)
-                       BUG();
-
+               BUG_ON(adapter->d_out.tx_skb);
                adapter->d_out.tx_skb = skb;
                FsmEvent(&adapter->d_out.fsm, EV_DOUT_START_XMIT, NULL);
                break;
 
        int slot;
        int proto;
 
-       if (net_dev->local->master)
-               BUG(); // we're called with the master device always
+       BUG_ON(net_dev->local->master); // we're called with the master device always
 
        slot = lp->ppp_slot;
        if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
                printk(KERN_DEBUG "ippp: no decompressor defined!\n");
                return skb;
        }
-       if (!stat) // if we have a compressor, stat has been set as well
-               BUG();
+       BUG_ON(!stat); // if we have a compressor, stat has been set as well
 
        if((master && *proto == PPP_COMP) || (!master && *proto == PPP_COMPFRAG) ) {
                // compressed packets are compressed by their protocol type