*     referencing boards when printing trace and stuff.
  */
 static char    *stl_brdnames[] = {
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
+       NULL,
        "EasyIO",
        "EC8/32-AT",
        "EC8/32-MC",
-       (char *) NULL,
-       (char *) NULL,
-       (char *) NULL,
+       NULL,
+       NULL,
+       NULL,
        "EC8/32-PCI",
        "EC8/64-PCI",
        "EasyIO-PCI",
        class_destroy(stallion_class);
 
        for (i = 0; (i < stl_nrbrds); i++) {
-               if ((brdp = stl_brds[i]) == (stlbrd_t *) NULL)
+               if ((brdp = stl_brds[i]) == NULL)
                        continue;
 
                free_irq(brdp->irq, brdp);
 
                for (j = 0; (j < STL_MAXPANELS); j++) {
                        panelp = brdp->panels[j];
-                       if (panelp == (stlpanel_t *) NULL)
+                       if (panelp == NULL)
                                continue;
                        for (k = 0; (k < STL_PORTSPERPANEL); k++) {
                                portp = panelp->ports[k];
-                               if (portp == (stlport_t *) NULL)
+                               if (portp == NULL)
                                        continue;
-                               if (portp->tty != (struct tty_struct *) NULL)
+                               if (portp->tty != NULL)
                                        stl_hangup(portp->tty);
                                kfree(portp->tx.buf);
                                kfree(portp);
                        release_region(brdp->ioaddr2, brdp->iosize2);
 
                kfree(brdp);
-               stl_brds[i] = (stlbrd_t *) NULL;
+               stl_brds[i] = NULL;
        }
 }
 
                memset(&conf, 0, sizeof(conf));
                if (stl_parsebrd(&conf, stl_brdsp[i]) == 0)
                        continue;
-               if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
+               if ((brdp = stl_allocbrd()) == NULL)
                        continue;
                stl_nrbrds = i + 1;
                brdp->brdnr = i;
 
        pr_debug("stl_parsebrd(confp=%p,argp=%p)\n", confp, argp);
 
-       if ((argp[0] == (char *) NULL) || (*argp[0] == 0))
+       if ((argp[0] == NULL) || (*argp[0] == 0))
                return 0;
 
        for (sp = argp[0], i = 0; ((*sp != 0) && (i < 25)); sp++, i++)
        confp->brdtype = stl_brdstr[i].type;
 
        i = 1;
-       if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
+       if ((argp[i] != NULL) && (*argp[i] != 0))
                confp->ioaddr1 = stl_atol(argp[i]);
        i++;
        if (confp->brdtype == BRD_ECH) {
-               if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
+               if ((argp[i] != NULL) && (*argp[i] != 0))
                        confp->ioaddr2 = stl_atol(argp[i]);
                i++;
        }
-       if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
+       if ((argp[i] != NULL) && (*argp[i] != 0))
                confp->irq = stl_atol(argp[i]);
        return 1;
 }
        if (brdnr >= stl_nrbrds)
                return -ENODEV;
        brdp = stl_brds[brdnr];
-       if (brdp == (stlbrd_t *) NULL)
+       if (brdp == NULL)
                return -ENODEV;
        minordev = MINOR2PORT(minordev);
        for (portnr = -1, panelnr = 0; (panelnr < STL_MAXPANELS); panelnr++) {
-               if (brdp->panels[panelnr] == (stlpanel_t *) NULL)
+               if (brdp->panels[panelnr] == NULL)
                        break;
                if (minordev < brdp->panels[panelnr]->nrports) {
                        portnr = minordev;
                return -ENODEV;
 
        portp = brdp->panels[panelnr]->ports[portnr];
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return -ENODEV;
 
 /*
        pr_debug("stl_close(tty=%p,filp=%p)\n", tty, filp);
 
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        spin_lock_irqsave(&stallion_lock, flags);
        stl_enablerxtx(portp, 0, 0);
        stl_flushbuffer(tty);
        portp->istate = 0;
-       if (portp->tx.buf != (char *) NULL) {
+       if (portp->tx.buf != NULL) {
                kfree(portp->tx.buf);
-               portp->tx.buf = (char *) NULL;
-               portp->tx.head = (char *) NULL;
-               portp->tx.tail = (char *) NULL;
+               portp->tx.buf = NULL;
+               portp->tx.head = NULL;
+               portp->tx.tail = NULL;
        }
        set_bit(TTY_IO_ERROR, &tty->flags);
        tty_ldisc_flush(tty);
 
        tty->closing = 0;
-       portp->tty = (struct tty_struct *) NULL;
+       portp->tty = NULL;
 
        if (portp->openwaitcnt) {
                if (portp->close_delay)
        pr_debug("stl_write(tty=%p,buf=%p,count=%d)\n", tty, buf, count);
 
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return 0;
-       if (portp->tx.buf == (char *) NULL)
+       if (portp->tx.buf == NULL)
                return 0;
 
 /*
 
        pr_debug("stl_putchar(tty=%p,ch=%x)\n", tty, ch);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
-       if (portp->tx.buf == (char *) NULL)
+       if (portp->tx.buf == NULL)
                return;
 
        head = portp->tx.head;
 
        pr_debug("stl_flushchars(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
-       if (portp->tx.buf == (char *) NULL)
+       if (portp->tx.buf == NULL)
                return;
 
        stl_startrxtx(portp, -1, 1);
 
        pr_debug("stl_writeroom(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return 0;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return 0;
-       if (portp->tx.buf == (char *) NULL)
+       if (portp->tx.buf == NULL)
                return 0;
 
        head = portp->tx.head;
 
        pr_debug("stl_charsinbuffer(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return 0;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return 0;
-       if (portp->tx.buf == (char *) NULL)
+       if (portp->tx.buf == NULL)
                return 0;
 
        head = portp->tx.head;
        }
 
        brdp = stl_brds[portp->brdnr];
-       if (brdp != (stlbrd_t *) NULL)
+       if (brdp != NULL)
                sio.irq = brdp->irq;
 
        return copy_to_user(sp, &sio, sizeof(struct serial_struct)) ? -EFAULT : 0;
 {
        stlport_t       *portp;
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return -ENODEV;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return -ENODEV;
        if (tty->flags & (1 << TTY_IO_ERROR))
                return -EIO;
        stlport_t       *portp;
        int rts = -1, dtr = -1;
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return -ENODEV;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return -ENODEV;
        if (tty->flags & (1 << TTY_IO_ERROR))
                return -EIO;
        pr_debug("stl_ioctl(tty=%p,file=%p,cmd=%x,arg=%lx)\n", tty, file, cmd,
                        arg);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return -ENODEV;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return -ENODEV;
 
        if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
 
        pr_debug("stl_settermios(tty=%p,old=%p)\n", tty, old);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        tiosp = tty->termios;
 
        pr_debug("stl_throttle(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        stl_flowctrl(portp, 0);
 }
 
        pr_debug("stl_unthrottle(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        stl_flowctrl(portp, 1);
 }
 
        pr_debug("stl_stop(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        stl_startrxtx(portp, -1, 0);
 }
 
        pr_debug("stl_start(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        stl_startrxtx(portp, -1, 1);
 }
 
        pr_debug("stl_hangup(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        portp->flags &= ~ASYNC_INITIALIZED;
        stl_flushbuffer(tty);
        portp->istate = 0;
        set_bit(TTY_IO_ERROR, &tty->flags);
-       if (portp->tx.buf != (char *) NULL) {
+       if (portp->tx.buf != NULL) {
                kfree(portp->tx.buf);
-               portp->tx.buf = (char *) NULL;
-               portp->tx.head = (char *) NULL;
-               portp->tx.tail = (char *) NULL;
+               portp->tx.buf = NULL;
+               portp->tx.head = NULL;
+               portp->tx.tail = NULL;
        }
-       portp->tty = (struct tty_struct *) NULL;
+       portp->tty = NULL;
        portp->flags &= ~ASYNC_NORMAL_ACTIVE;
        portp->refcount = 0;
        wake_up_interruptible(&portp->open_wait);
 
        pr_debug("stl_flushbuffer(tty=%p)\n", tty);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        stl_flush(portp);
 
        pr_debug("stl_breakctl(tty=%p,state=%d)\n", tty, state);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        stl_sendbreak(portp, ((state == -1) ? 1 : 2));
 
        pr_debug("stl_waituntilsent(tty=%p,timeout=%d)\n", tty, timeout);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        if (timeout == 0)
 
        pr_debug("stl_sendxchar(tty=%p,ch=%x)\n", tty, ch);
 
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
        portp = tty->driver_data;
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        if (ch == STOP_CHAR(tty))
  */
        for (brdnr = 0; (brdnr < stl_nrbrds); brdnr++) {
                brdp = stl_brds[brdnr];
-               if (brdp == (stlbrd_t *) NULL)
+               if (brdp == NULL)
                        continue;
                if (brdp->state == 0)
                        continue;
                totalport = brdnr * STL_MAXPORTS;
                for (panelnr = 0; (panelnr < brdp->nrpanels); panelnr++) {
                        panelp = brdp->panels[panelnr];
-                       if (panelp == (stlpanel_t *) NULL)
+                       if (panelp == NULL)
                                continue;
 
                        maxoff = curoff + (panelp->nrports * MAXLINE);
                        for (portnr = 0; (portnr < panelp->nrports); portnr++,
                            totalport++) {
                                portp = panelp->ports[portnr];
-                               if (portp == (stlport_t *) NULL)
+                               if (portp == NULL)
                                        continue;
                                if (off >= (curoff += MAXLINE))
                                        continue;
 
 static irqreturn_t stl_intr(int irq, void *dev_id)
 {
-       stlbrd_t        *brdp = (stlbrd_t *) dev_id;
+       stlbrd_t *brdp = dev_id;
 
        pr_debug("stl_intr(brdp=%p,irq=%d)\n", brdp, irq);
 
 
        pr_debug("stl_offintr(portp=%p)\n", portp);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        tty = portp->tty;
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
 
        lock_kernel();
        panelp->iobase = brdp->ioaddr1;
        panelp->hwid = status;
        if ((status & EIO_IDBITMASK) == EIO_MK3) {
-               panelp->uartp = (void *) &stl_sc26198uart;
+               panelp->uartp = &stl_sc26198uart;
                panelp->isr = stl_sc26198intr;
        } else {
-               panelp->uartp = (void *) &stl_cd1400uart;
+               panelp->uartp = &stl_cd1400uart;
                panelp->isr = stl_cd1400eiointr;
        }
 
                brdp->bnkstataddr[banknr++] = ioaddr + ECH_PNLSTATUS;
 
                if (status & ECH_PNLXPID) {
-                       panelp->uartp = (void *) &stl_sc26198uart;
+                       panelp->uartp = &stl_sc26198uart;
                        panelp->isr = stl_sc26198intr;
                        if (status & ECH_PNL16PORT) {
                                panelp->nrports = 16;
                                panelp->nrports = 8;
                        }
                } else {
-                       panelp->uartp = (void *) &stl_cd1400uart;
+                       panelp->uartp = &stl_cd1400uart;
                        panelp->isr = stl_cd1400echintr;
                        if (status & ECH_PNL16PORT) {
                                panelp->nrports = 16;
        }
 
        for (i = 0; (i < STL_MAXPANELS); i++)
-               if (brdp->panels[i] != (stlpanel_t *) NULL)
+               if (brdp->panels[i] != NULL)
                        stl_initports(brdp, brdp->panels[i]);
 
        printk("STALLION: %s found, board=%d io=%x irq=%d "
        int     i;
 
        for (i = 0; (i < STL_MAXBRDS); i++) {
-               if (stl_brds[i] == (stlbrd_t *) NULL) {
+               if (stl_brds[i] == NULL) {
                        if (i >= stl_nrbrds)
                                stl_nrbrds = i + 1;
                        return(i);
 
        if (pci_enable_device(devp))
                return(-EIO);
-       if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
+       if ((brdp = stl_allocbrd()) == NULL)
                return(-ENOMEM);
        if ((brdp->brdnr = stl_getbrdnr()) < 0) {
                printk("STALLION: too many boards found, "
        for (i = 0; (i < stl_nrbrds); i++) {
                confp = &stl_brdconf[i];
                stl_parsebrd(confp, stl_brdsp[i]);
-               if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
+               if ((brdp = stl_allocbrd()) == NULL)
                        return(-ENOMEM);
                brdp->brdnr = i;
                brdp->brdtype = confp->brdtype;
        if (stl_brdstats.brd >= STL_MAXBRDS)
                return(-ENODEV);
        brdp = stl_brds[stl_brdstats.brd];
-       if (brdp == (stlbrd_t *) NULL)
+       if (brdp == NULL)
                return(-ENODEV);
 
        memset(&stl_brdstats, 0, sizeof(combrd_t));
        stlpanel_t      *panelp;
 
        if ((brdnr < 0) || (brdnr >= STL_MAXBRDS))
-               return((stlport_t *) NULL);
+               return(NULL);
        brdp = stl_brds[brdnr];
-       if (brdp == (stlbrd_t *) NULL)
-               return((stlport_t *) NULL);
+       if (brdp == NULL)
+               return(NULL);
        if ((panelnr < 0) || (panelnr >= brdp->nrpanels))
-               return((stlport_t *) NULL);
+               return(NULL);
        panelp = brdp->panels[panelnr];
-       if (panelp == (stlpanel_t *) NULL)
-               return((stlport_t *) NULL);
+       if (panelp == NULL)
+               return(NULL);
        if ((portnr < 0) || (portnr >= panelp->nrports))
-               return((stlport_t *) NULL);
+               return(NULL);
        return(panelp->ports[portnr]);
 }
 
                        return -EFAULT;
                portp = stl_getport(stl_comstats.brd, stl_comstats.panel,
                        stl_comstats.port);
-               if (portp == (stlport_t *) NULL)
+               if (portp == NULL)
                        return(-ENODEV);
        }
 
        portp->stats.rxbuffered = 0;
 
        spin_lock_irqsave(&stallion_lock, flags);
-       if (portp->tty != (struct tty_struct *) NULL) {
+       if (portp->tty != NULL) {
                if (portp->tty->driver_data == portp) {
                        portp->stats.ttystate = portp->tty->flags;
                        /* No longer available as a statistic */
                        portp->stats.rxbuffered = 1; /*portp->tty->flip.count; */
-                       if (portp->tty->termios != (struct termios *) NULL) {
+                       if (portp->tty->termios != NULL) {
                                portp->stats.cflags = portp->tty->termios->c_cflag;
                                portp->stats.iflags = portp->tty->termios->c_iflag;
                                portp->stats.oflags = portp->tty->termios->c_oflag;
                        return -EFAULT;
                portp = stl_getport(stl_comstats.brd, stl_comstats.panel,
                        stl_comstats.port);
-               if (portp == (stlport_t *) NULL)
+               if (portp == NULL)
                        return(-ENODEV);
        }
 
        pr_debug("stl_cd1400portinit(brdp=%p,panelp=%p,portp=%p)\n", brdp,
                        panelp, portp);
 
-       if ((brdp == (stlbrd_t *) NULL) || (panelp == (stlpanel_t *) NULL) ||
-           (portp == (stlport_t *) NULL))
+       if ((brdp == NULL) || (panelp == NULL) ||
+           (portp == NULL))
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
        sreroff = 0;
 
        brdp = stl_brds[portp->brdnr];
-       if (brdp == (stlbrd_t *) NULL)
+       if (brdp == NULL)
                return;
 
 /*
 
        pr_debug("stl_cd1400flowctrl(portp=%p,state=%x)\n", portp, state);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        tty = portp->tty;
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
 
        pr_debug("stl_cd1400sendflow(portp=%p,state=%x)\n", portp, state);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        tty = portp->tty;
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
 
        pr_debug("stl_cd1400flush(portp=%p)\n", portp);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
 {
        pr_debug("stl_cd1400datastate(portp=%p)\n", portp);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return 0;
 
        return test_bit(ASYI_TXBUSY, &portp->istate) ? 1 : 0;
        pr_debug("stl_sc26198portinit(brdp=%p,panelp=%p,portp=%p)\n", brdp,
                        panelp, portp);
 
-       if ((brdp == (stlbrd_t *) NULL) || (panelp == (stlpanel_t *) NULL) ||
-           (portp == (stlport_t *) NULL))
+       if ((brdp == NULL) || (panelp == NULL) ||
+           (portp == NULL))
                return;
 
        portp->ioaddr = panelp->iobase + ((portp->portnr < 8) ? 0 : 4);
        imroff = 0;
 
        brdp = stl_brds[portp->brdnr];
-       if (brdp == (stlbrd_t *) NULL)
+       if (brdp == NULL)
                return;
 
 /*
 
        pr_debug("stl_sc26198flowctrl(portp=%p,state=%x)\n", portp, state);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        tty = portp->tty;
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
 
        pr_debug("stl_sc26198sendflow(portp=%p,state=%x)\n", portp, state);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
        tty = portp->tty;
-       if (tty == (struct tty_struct *) NULL)
+       if (tty == NULL)
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
 
        pr_debug("stl_sc26198flush(portp=%p)\n", portp);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        spin_lock_irqsave(&brd_lock, flags);
 
        pr_debug("stl_sc26198datastate(portp=%p)\n", portp);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return 0;
        if (test_bit(ASYI_TXBUSY, &portp->istate))
                return 1;
 
        pr_debug("stl_sc26198wait(portp=%p)\n", portp);
 
-       if (portp == (stlport_t *) NULL)
+       if (portp == NULL)
                return;
 
        for (i = 0; (i < 20); i++)
  *     flow control modes of the sc26198.
  */
        if (test_bit(ASYI_TXFLOWED, &portp->istate)) {
-               if ((tty != (struct tty_struct *) NULL) &&
-                   (tty->termios != (struct termios *) NULL) &&
+               if ((tty != NULL) &&
+                   (tty->termios != NULL) &&
                    (tty->termios->c_iflag & IXANY)) {
                        stl_sc26198txunflow(portp, tty);
                }
        if (status & SR_RXBREAK)
                portp->stats.rxbreaks++;
 
-       if ((tty != (struct tty_struct *) NULL) &&
+       if ((tty != NULL) &&
            ((portp->rxignoremsk & status) == 0)) {
                if (portp->rxmarkmsk & status) {
                        if (status & SR_RXBREAK) {