bool dead;              /* Refuse re-open */
        /* Flow control */
        bool throttled;         /* Private copy of throttle state */
-       int constipated;        /* Throttle status for outgoing */
+       bool constipated;       /* Throttle status for outgoing */
        /* Packetised I/O */
        struct sk_buff *skb;    /* Frame being sent */
        struct sk_buff_head skb_list;   /* Queued frames */
        int initiator;                  /* Did we initiate connection */
        bool dead;                      /* Has the mux been shut down */
        struct gsm_dlci *dlci[NUM_DLCI];
-       int constipated;                /* Asked by remote to shut up */
+       bool constipated;               /* Asked by remote to shut up */
 
        spinlock_t tx_lock;
        unsigned int tx_bytes;          /* TX data outstanding */
        fc = (modem & MDM_FC) || !(modem & MDM_RTR);
        if (fc && !dlci->constipated) {
                /* Need to throttle our output on this device */
-               dlci->constipated = 1;
+               dlci->constipated = true;
        } else if (!fc && dlci->constipated) {
-               dlci->constipated = 0;
+               dlci->constipated = false;
                gsm_dlci_data_kick(dlci);
        }
 
                break;
        case CMD_FCON:
                /* Modem can accept data again */
-               gsm->constipated = 0;
+               gsm->constipated = false;
                gsm_control_reply(gsm, CMD_FCON, NULL, 0);
                /* Kick the link in case it is idling */
                spin_lock_irqsave(&gsm->tx_lock, flags);
                break;
        case CMD_FCOFF:
                /* Modem wants us to STFU */
-               gsm->constipated = 1;
+               gsm->constipated = true;
                gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
                break;
        case CMD_MSC: