rs_wait_until_sent(tty, info->timeout);
        }
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       rs_flush_buffer(tty);
                
        tty_ldisc_flush(tty);
        tty->closing = 0;
                return; /* Just in case.... */
 
        orig_jiffies = jiffies;
+
+       lock_kernel();
        /*
         * Set the check interval to be 1/5 of the estimated time to
         * send a single character, and make it at least 1.  The check
                        break;
        }
        __set_current_state(TASK_RUNNING);
+       unlock_kernel();
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
        printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 #endif
 
                return;         /* Just in case.... */
 
        orig_jiffies = jiffies;
+       lock_kernel();
        /*
         * Set the check interval to be 1/5 of the estimated time to
         * send a single character, and make it at least 1.  The check
        }
        /* Run one more char cycle */
        msleep_interruptible(jiffies_to_msecs(char_time * 5));
+       unlock_kernel();
 #ifdef CY_DEBUG_WAIT_UNTIL_SENT
        printk(KERN_DEBUG "Clean (jiff=%lu)...done\n", jiffies);
 #endif
 }
 
+static void cy_flush_buffer(struct tty_struct *tty)
+{
+       struct cyclades_port *info = tty->driver_data;
+       struct cyclades_card *card;
+       int channel, retval;
+       unsigned long flags;
+
+#ifdef CY_DEBUG_IO
+       printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);
+#endif
+
+       if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))
+               return;
+
+       card = info->card;
+       channel = info->line - card->first_line;
+
+       spin_lock_irqsave(&card->card_lock, flags);
+       info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
+       spin_unlock_irqrestore(&card->card_lock, flags);
+
+       if (IS_CYC_Z(*card)) {  /* If it is a Z card, flush the on-board
+                                          buffers as well */
+               spin_lock_irqsave(&card->card_lock, flags);
+               retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);
+               if (retval != 0) {
+                       printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "
+                               "was %x\n", info->line, retval);
+               }
+               spin_unlock_irqrestore(&card->card_lock, flags);
+       }
+       tty_wakeup(tty);
+}                              /* cy_flush_buffer */
+
+
 /*
  * This routine is called when a particular tty device is closed.
  */
 
        spin_unlock_irqrestore(&card->card_lock, flags);
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       cy_flush_buffer(tty);
        tty_ldisc_flush(tty);
        spin_lock_irqsave(&card->card_lock, flags);
 
                int char_count;
                __u32 tx_put, tx_get, tx_bufsize;
 
+               lock_kernel();
                firm_id = card->base_addr + ID_ADDRESS;
                zfw_ctrl = card->base_addr +
                        (readl(&firm_id->zfwctrl_addr) & 0xfffff);
                printk(KERN_DEBUG "cyc:cy_chars_in_buffer ttyC%d %d\n",
                        info->line, info->xmit_cnt + char_count);
 #endif
+               unlock_kernel();
                return info->xmit_cnt + char_count;
        }
 #endif                         /* Z_EXT_CHARS_IN_BUFFER */
        }
 }                              /* cy_start */
 
-static void cy_flush_buffer(struct tty_struct *tty)
-{
-       struct cyclades_port *info = tty->driver_data;
-       struct cyclades_card *card;
-       int channel, retval;
-       unsigned long flags;
-
-#ifdef CY_DEBUG_IO
-       printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);
-#endif
-
-       if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))
-               return;
-
-       card = info->card;
-       channel = info->line - card->first_line;
-
-       spin_lock_irqsave(&card->card_lock, flags);
-       info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
-       spin_unlock_irqrestore(&card->card_lock, flags);
-
-       if (IS_CYC_Z(*card)) {  /* If it is a Z card, flush the on-board
-                                          buffers as well */
-               spin_lock_irqsave(&card->card_lock, flags);
-               retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);
-               if (retval != 0) {
-                       printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "
-                               "was %x\n", info->line, retval);
-               }
-               spin_unlock_irqrestore(&card->card_lock, flags);
-       }
-       tty_wakeup(tty);
-}                              /* cy_flush_buffer */
-
 /*
  * cy_hangup() --- called by tty_hangup() when a hangup is signaled.
  */
 
 static void pc_close(struct tty_struct *, struct file *);
 static void shutdown(struct channel *);
 static void pc_hangup(struct tty_struct *);
-static void pc_put_char(struct tty_struct *, unsigned char);
 static int pc_write_room(struct tty_struct *);
 static int pc_chars_in_buffer(struct tty_struct *);
 static void pc_flush_buffer(struct tty_struct *);
                        setup_empty_event(tty, ch);
                        tty_wait_until_sent(tty, 3000); /* 30 seconds timeout */
                }
-               if (tty->driver->flush_buffer)
-                       tty->driver->flush_buffer(tty);
+               pc_flush_buffer(tty);
 
                tty_ldisc_flush(tty);
                shutdown(ch);
        if ((ch = verifyChannel(tty)) != NULL) {
                unsigned long flags;
 
-               if (tty->driver->flush_buffer)
-                       tty->driver->flush_buffer(tty);
+               pc_flush_buffer(tty);
                tty_ldisc_flush(tty);
                shutdown(ch);
 
        return amountCopied;
 }
 
-static void pc_put_char(struct tty_struct *tty, unsigned char c)
-{
-       pc_write(tty, &c, 1);
-}
-
 static int pc_write_room(struct tty_struct *tty)
 {
        int remain;
        .flush_buffer = pc_flush_buffer,
        .chars_in_buffer = pc_chars_in_buffer,
        .flush_chars = pc_flush_chars,
-       .put_char = pc_put_char,
        .ioctl = pc_ioctl,
        .set_termios = pc_set_termios,
        .stop = pc_stop,
 
                rs_wait_until_sent(tty, info->timeout);
        }
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       rs_flush_buffer(tty);
        tty_ldisc_flush(tty);
        tty->closing = 0;
        info->tty = NULL;
 
 
        port->flags &= ~GS_ACTIVE;
 
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       gs_flush_buffer(tty);
 
        tty_ldisc_flush(tty);
        tty->closing = 0;
 
        }
 }
 
+static void isicom_flush_buffer(struct tty_struct *tty)
+{
+       struct isi_port *port = tty->driver_data;
+       struct isi_board *card = port->card;
+       unsigned long flags;
+
+       if (isicom_paranoia_check(port, tty->name, "isicom_flush_buffer"))
+               return;
+
+       spin_lock_irqsave(&card->card_lock, flags);
+       port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
+       spin_unlock_irqrestore(&card->card_lock, flags);
+
+       tty_wakeup(tty);
+}
+
 static void isicom_close(struct tty_struct *tty, struct file *filp)
 {
        struct isi_port *port = tty->driver_data;
        isicom_shutdown_port(port);
        spin_unlock_irqrestore(&card->card_lock, flags);
 
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       isicom_flush_buffer(tty);
        tty_ldisc_flush(tty);
 
        spin_lock_irqsave(&card->card_lock, flags);
        wake_up_interruptible(&port->open_wait);
 }
 
-/* flush_buffer et all */
-static void isicom_flush_buffer(struct tty_struct *tty)
-{
-       struct isi_port *port = tty->driver_data;
-       struct isi_board *card = port->card;
-       unsigned long flags;
-
-       if (isicom_paranoia_check(port, tty->name, "isicom_flush_buffer"))
-               return;
-
-       spin_lock_irqsave(&card->card_lock, flags);
-       port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
-       spin_unlock_irqrestore(&card->card_lock, flags);
-
-       tty_wakeup(tty);
-}
 
 /*
  * Driver init and deinit functions
 
         */
        if (ch == NULL)
                return 0;
+       lock_kernel();
        chars = MoxaPortTxQueue(ch);
        if (chars) {
                /*
                if (!(ch->statusflags & EMPTYWAIT))
                        moxa_setup_empty_event(tty);
        }
+       unlock_kernel();
        return chars;
 }
 
 
        return 0;
 }
 
+static void mxser_flush_buffer(struct tty_struct *tty)
+{
+       struct mxser_port *info = tty->driver_data;
+       char fcr;
+       unsigned long flags;
+
+
+       spin_lock_irqsave(&info->slock, flags);
+       info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
+
+       fcr = inb(info->ioaddr + UART_FCR);
+       outb((fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
+               info->ioaddr + UART_FCR);
+       outb(fcr, info->ioaddr + UART_FCR);
+
+       spin_unlock_irqrestore(&info->slock, flags);
+
+       tty_wakeup(tty);
+}
+
+
 /*
  * This routine is called when the serial port gets closed.  First, we
  * wait for the last remaining data to be sent.  Then, we unlink its
        }
        mxser_shutdown(info);
 
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
-
+       mxser_flush_buffer(tty);
        tty_ldisc_flush(tty);
 
        tty->closing = 0;
        return info->xmit_cnt;
 }
 
-static void mxser_flush_buffer(struct tty_struct *tty)
-{
-       struct mxser_port *info = tty->driver_data;
-       char fcr;
-       unsigned long flags;
-
-
-       spin_lock_irqsave(&info->slock, flags);
-       info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
-
-       fcr = inb(info->ioaddr + UART_FCR);
-       outb((fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
-               info->ioaddr + UART_FCR);
-       outb(fcr, info->ioaddr + UART_FCR);
-
-       spin_unlock_irqrestore(&info->slock, flags);
-
-       tty_wakeup(tty);
-}
-
 /*
  * ------------------------------------------------------------
  * friends of mxser_ioctl()
                timeout, char_time);
        printk("jiff=%lu...", jiffies);
 #endif
+       lock_kernel();
        while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
                printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
                        break;
        }
        set_current_state(TASK_RUNNING);
+       unlock_kernel();
 
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
        printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 
        const struct ctrl_dl *ctrl_dl = &port->ctrl_dl;
        const struct ctrl_ul *ctrl_ul = &port->ctrl_ul;
 
+       /* Note: these could change under us but it is not clear this
+          matters if so */
        return  (ctrl_ul->RTS ? TIOCM_RTS : 0) |
                (ctrl_ul->DTR ? TIOCM_DTR : 0) |
                (ctrl_dl->DCD ? TIOCM_CAR : 0) |
        spin_unlock_irqrestore(&dc->spin_mutex, flags);
 }
 
-/* just to discard single character writes */
-static void ntty_put_char(struct tty_struct *tty, unsigned char c)
-{
-       /*
-        * card does not react correct when we write single chars
-        * to the card, so we discard them
-        */
-       DBG2("PUT CHAR Function: %c", c);
-}
-
 /* Returns number of chars in buffer, called by tty layer */
 static s32 ntty_chars_in_buffer(struct tty_struct *tty)
 {
        .unthrottle = ntty_unthrottle,
        .throttle = ntty_throttle,
        .chars_in_buffer = ntty_chars_in_buffer,
-       .put_char = ntty_put_char,
        .tiocmget = ntty_tiocmget,
        .tiocmset = ntty_tiocmset,
 };
 
  * The wrappers maintain line discipline references
  * while calling into the line discipline.
  *
- * ldisc_flush_buffer - flush line discipline receive buffers
  * ldisc_receive_buf  - pass receive data to line discipline
  */
 
-static void ldisc_flush_buffer(struct tty_struct *tty)
-{
-       struct tty_ldisc *ld = tty_ldisc_ref(tty);
-       if (ld) {
-               if (ld->flush_buffer)
-                       ld->flush_buffer(tty);
-               tty_ldisc_deref(ld);
-       }
-}
-
 static void ldisc_receive_buf(struct tty_struct *tty,
                              const __u8 *data, char *flags, int count)
 {
        if (info->flags & ASYNC_INITIALIZED)
                mgslpc_wait_until_sent(tty, info->timeout);
 
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       mgslpc_flush_buffer(tty);
 
-       ldisc_flush_buffer(tty);
+       tty_ldisc_flush(tty);
 
        shutdown(info);
 
 
        return 0;
 }
 
+static void rc_flush_buffer(struct tty_struct *tty)
+{
+       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       unsigned long flags;
+
+       if (rc_paranoia_check(port, tty->name, "rc_flush_buffer"))
+               return;
+
+       spin_lock_irqsave(&riscom_lock, flags);
+
+       port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
+
+       spin_unlock_irqrestore(&riscom_lock, flags);
+
+       tty_wakeup(tty);
+}
+
+
 static void rc_close(struct tty_struct * tty, struct file * filp)
 {
        struct riscom_port *port = (struct riscom_port *) tty->driver_data;
                }
        }
        rc_shutdown_port(bp, port);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       rc_flush_buffer(tty);
        tty_ldisc_flush(tty);
 
        tty->closing = 0;
        return port->xmit_cnt;
 }
 
-static void rc_flush_buffer(struct tty_struct *tty)
-{
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
-       unsigned long flags;
-                               
-       if (rc_paranoia_check(port, tty->name, "rc_flush_buffer"))
-               return;
-
-       spin_lock_irqsave(&riscom_lock, flags);
-
-       port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
-
-       spin_unlock_irqrestore(&riscom_lock, flags);
-       
-       tty_wakeup(tty);
-}
-
 static int rc_tiocmget(struct tty_struct *tty, struct file *file)
 {
        struct riscom_port *port = (struct riscom_port *)tty->driver_data;
 
               jiffies);
        printk(KERN_INFO "cps=%d...\n", info->cps);
 #endif
+       lock_kernel();
        while (1) {
                txcnt = sGetTxCnt(cp);
                if (!txcnt) {
                        break;
        }
        __set_current_state(TASK_RUNNING);
+       unlock_kernel();
 #ifdef ROCKET_DEBUG_WAIT_UNTIL_SENT
        printk(KERN_INFO "txcnt = %d (jiff=%lu)...done\n", txcnt, jiffies);
 #endif
 
        if (info->flags & ASYNC_INITIALIZED)
                tty_wait_until_sent(tty, 3000); /* 30 seconds timeout */
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       cy_flush_buffer(tty);
        tty_ldisc_flush(tty);
        info->tty = NULL;
        if (info->blocked_open) {
 
        return 0;
 }
 
+static void sx_flush_buffer(struct tty_struct *tty)
+{
+       struct specialix_port *port = (struct specialix_port *)tty->driver_data;
+       unsigned long flags;
+       struct specialix_board  * bp;
+
+       func_enter();
+
+       if (sx_paranoia_check(port, tty->name, "sx_flush_buffer")) {
+               func_exit();
+               return;
+       }
+
+       bp = port_Board(port);
+       spin_lock_irqsave(&port->lock, flags);
+       port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
+       spin_unlock_irqrestore(&port->lock, flags);
+       tty_wakeup(tty);
+
+       func_exit();
+}
 
 static void sx_close(struct tty_struct * tty, struct file * filp)
 {
        }
 
        sx_shutdown_port(bp, port);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       sx_flush_buffer(tty);
        tty_ldisc_flush(tty);
        spin_lock_irqsave(&port->lock, flags);
        tty->closing = 0;
 }
 
 
-static void sx_flush_buffer(struct tty_struct *tty)
-{
-       struct specialix_port *port = (struct specialix_port *)tty->driver_data;
-       unsigned long flags;
-       struct specialix_board  * bp;
-
-       func_enter();
-
-       if (sx_paranoia_check(port, tty->name, "sx_flush_buffer")) {
-               func_exit();
-               return;
-       }
-
-       bp = port_Board(port);
-       spin_lock_irqsave(&port->lock, flags);
-       port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
-       spin_unlock_irqrestore(&port->lock, flags);
-       tty_wakeup(tty);
-
-       func_exit();
-}
-
 
 static int sx_tiocmget(struct tty_struct *tty, struct file *file)
 {
 
                timeout = HZ;
        tend = jiffies + timeout;
 
+       lock_kernel();
        while (stl_datastate(portp)) {
                if (signal_pending(current))
                        break;
                if (time_after_eq(jiffies, tend))
                        break;
        }
+       unlock_kernel();
 }
 
 /*****************************************************************************/
 
        if (info->flags & ASYNC_INITIALIZED)
                mgsl_wait_until_sent(tty, info->timeout);
 
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       mgsl_flush_buffer(tty);
 
        tty_ldisc_flush(tty);
                
         * interval should also be less than the timeout.
         * Note: use tight timings here to satisfy the NIST-PCTS.
         */ 
-       
+
+       lock_kernel();
        if ( info->params.data_rate ) {
                char_time = info->timeout/(32 * 5);
                if (!char_time)
                                break;
                }
        }
+       unlock_kernel();
       
 exit:
        if (debug_level >= DEBUG_LEVEL_INFO)
 
 
        if (info->flags & ASYNC_INITIALIZED)
                wait_until_sent(tty, info->timeout);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       flush_buffer(tty);
        tty_ldisc_flush(tty);
 
        shutdown(info);
         * Note: use tight timings here to satisfy the NIST-PCTS.
         */
 
+       lock_kernel();
+
        if (info->params.data_rate) {
                char_time = info->timeout/(32 * 5);
                if (!char_time)
                if (timeout && time_after(jiffies, orig_jiffies + timeout))
                        break;
        }
+       unlock_kernel();
 
 exit:
        DBGINFO(("%s wait_until_sent exit\n", info->device_name));
 
        if (info->flags & ASYNC_INITIALIZED)
                wait_until_sent(tty, info->timeout);
 
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       flush_buffer(tty);
 
        tty_ldisc_flush(tty);
 
        if (sanity_check(info, tty->name, "wait_until_sent"))
                return;
 
+       lock_kernel();
+
        if (!(info->flags & ASYNC_INITIALIZED))
                goto exit;
 
        }
 
 exit:
+       unlock_kernel();
        if (debug_level >= DEBUG_LEVEL_INFO)
                printk("%s(%d):%s wait_until_sent() exit\n",
                         __FILE__,__LINE__, info->device_name );
        if (sanity_check(info, tty->name, "write_room"))
                return 0;
 
+       lock_kernel();
        if (info->params.mode == MGSL_MODE_HDLC) {
                ret = (info->tx_active) ? 0 : HDLC_MAX_FRAME_SIZE;
        } else {
                if (ret < 0)
                        ret = 0;
        }
+       unlock_kernel();
 
        if (debug_level >= DEBUG_LEVEL_INFO)
                printk("%s(%d):%s write_room()=%d\n",
 
  *     not in the foreground, send a SIGTTOU.  If the signal is blocked or
  *     ignored, go ahead and perform the operation.  (POSIX 7.2)
  *
- *     Locking: ctrl_lock - FIXME: review this
+ *     Locking: ctrl_lock
  */
 
 int tty_check_change(struct tty_struct *tty)
 
 static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
 {
        int canon_change;
-       struct ktermios old_termios = *tty->termios;
+       struct ktermios old_termios;
        struct tty_ldisc *ld;
        unsigned long flags;
 
        /* FIXME: we need to decide on some locking/ordering semantics
           for the set_termios notification eventually */
        mutex_lock(&tty->termios_mutex);
-
+       old_termios = *tty->termios;
        *tty->termios = *new_termios;
        unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
        canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
        if (retval)
                return retval;
 
+       mutex_lock(&tty->termios_mutex);
        memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
+       mutex_unlock(&tty->termios_mutex);
 
        if (opt & TERMIOS_TERMIO) {
                if (user_termio_to_kernel_termios(&tmp_termios,
 {
        struct tchars tmp;
 
+       mutex_lock(&tty->termios_mutex);
        tmp.t_intrc = tty->termios->c_cc[VINTR];
        tmp.t_quitc = tty->termios->c_cc[VQUIT];
        tmp.t_startc = tty->termios->c_cc[VSTART];
        tmp.t_stopc = tty->termios->c_cc[VSTOP];
        tmp.t_eofc = tty->termios->c_cc[VEOF];
        tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
+       mutex_unlock(&tty->termios_mutex);
        return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
 
        if (copy_from_user(&tmp, tchars, sizeof(tmp)))
                return -EFAULT;
+       mutex_lock(&tty->termios_mutex);
        tty->termios->c_cc[VINTR] = tmp.t_intrc;
        tty->termios->c_cc[VQUIT] = tmp.t_quitc;
        tty->termios->c_cc[VSTART] = tmp.t_startc;
        tty->termios->c_cc[VSTOP] = tmp.t_stopc;
        tty->termios->c_cc[VEOF] = tmp.t_eofc;
        tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
+       mutex_unlock(&tty->termios_mutex);
        return 0;
 }
 #endif
 {
        struct ltchars tmp;
 
+       mutex_lock(&tty->termios_mutex);
        tmp.t_suspc = tty->termios->c_cc[VSUSP];
        /* what is dsuspc anyway? */
        tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
        tmp.t_flushc = tty->termios->c_cc[VEOL2];
        tmp.t_werasc = tty->termios->c_cc[VWERASE];
        tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
+       mutex_unlock(&tty->termios_mutex);
        return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
        if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
                return -EFAULT;
 
+       mutex_lock(&tty->termios_mutex);
        tty->termios->c_cc[VSUSP] = tmp.t_suspc;
        /* what is dsuspc anyway? */
        tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
        tty->termios->c_cc[VEOL2] = tmp.t_flushc;
        tty->termios->c_cc[VWERASE] = tmp.t_werasc;
        tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
+       mutex_unlock(&tty->termios_mutex);
        return 0;
 }
 #endif
 
        }
        dev->modempoll--;
        isdn_tty_shutdown(info);
-       
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       isdn_tty_flush_buffer(tty);
        tty_ldisc_flush(tty);
        info->tty = NULL;
        info->ncarrier = 0;
 
                        tty_wait_until_sent(tty, 0);
                        send_break(info, arg ? arg*(100) : 250);
                        return 0;
-               case TIOCGSOFTCAR:
-                       error = put_user(C_CLOCAL(tty) ? 1 : 0,
-                                   (unsigned long *) arg);
-                       if (error)
-                               return error;
-                       return 0;
-               case TIOCSSOFTCAR:
-                       get_user(arg, (unsigned long *) arg);
-                       tty->termios->c_cflag =
-                               ((tty->termios->c_cflag & ~CLOCAL) |
-                                (arg ? CLOCAL : 0));
-                       return 0;
                case TIOCGSERIAL:
                        if (access_ok(VERIFY_WRITE, (void *) arg,
                                                sizeof(struct serial_struct)))
 {
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
-       if (tty->termios->c_cflag == old_termios->c_cflag)
-               return;
-
        change_speed(info);
 
        if ((old_termios->c_cflag & CRTSCTS) &&
        uart->ustcnt &= ~(USTCNT_RXEN | USTCNT_RX_INTR_MASK);
 
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       rs_flush_buffer(tty);
                
        tty_ldisc_flush(tty);
        tty->closing = 0;
 
                                return retval;
                        end_break(info);
                        return 0;
-               case TIOCGSOFTCAR:
-                       /* return put_user(C_CLOCAL(tty) ? 1 : 0, (int *) arg); */
-                       put_user(C_CLOCAL(tty) ? 1 : 0, (int *) arg);
-                       return 0;
-               case TIOCSSOFTCAR:
-                       error = get_user(arg, (unsigned int *) arg); 
-                       if (error)
-                               return error;
-                       tty->termios->c_cflag =
-                               ((tty->termios->c_cflag & ~CLOCAL) |
-                                (arg ? CLOCAL : 0));
-                       return 0;
 #ifdef maybe
                case TIOCSERGETLSR: /* Get line status register */
                        return get_lsr_info(info, (unsigned int *) arg);
                rs_360_wait_until_sent(tty, info->timeout);
        }
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       rs_360_flush_buffer(tty);
        tty_ldisc_flush(tty);           
        tty->closing = 0;
        info->event = 0;
        printk("jiff=%lu...", jiffies);
 #endif
 
+       lock_kernel();
        /* We go through the loop at least once because we can't tell
         * exactly when the last character exits the shifter.  There can
         * be at least two characters waiting to be sent after the buffers
                        bdp--;
        } while (bdp->status & BD_SC_READY);
        current->state = TASK_RUNNING;
+       unlock_kernel();
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
        printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 #endif
 
                unsigned int set, unsigned int clear)
 {
        struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+       unsigned long flags;
 
-       lock_kernel();
+       local_irq_save(flags);
 
        if (clear & TIOCM_RTS)
                e100_rts(info, 0);
        if (set & TIOCM_CD)
                e100_cd_out(info, 1);
 
-       unlock_kernel();
+       local_irq_restore(flags);
        return 0;
 }
 
 {
        struct e100_serial *info = (struct e100_serial *)tty->driver_data;
        unsigned int result;
+       unsigned long flags;
+
+       local_irq_save(flags);
 
-       lock_kernel();
        result =
                (!E100_RTS_GET(info) ? TIOCM_RTS : 0)
                | (!E100_DTR_GET(info) ? TIOCM_DTR : 0)
                | (!E100_CD_GET(info) ? TIOCM_CAR : 0)
                | (!E100_CTS_GET(info) ? TIOCM_CTS : 0);
 
-       unlock_kernel();
+       local_irq_restore(flags);
 
 #ifdef SERIAL_DEBUG_IO
        printk(KERN_DEBUG "ser%i: modem state: %i 0x%08X\n",
 {
        struct e100_serial *info = (struct e100_serial *)tty->driver_data;
 
-       if (tty->termios->c_cflag == old_termios->c_cflag &&
-           tty->termios->c_iflag == old_termios->c_iflag)
-               return;
-
        change_speed(info);
 
        /* Handle turning off CRTSCTS */
 #endif
 
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
-       if (tty->ldisc.flush_buffer)
-               tty->ldisc.flush_buffer(tty);
+       rs_flush_buffer(tty);
+       tty_ldisc_flush_buffer(tty);
        tty->closing = 0;
        info->event = 0;
        info->tty = 0;
         * Check R_DMA_CHx_STATUS bit 0-6=number of available bytes in FIFO
         * R_DMA_CHx_HWSW bit 31-16=nbr of bytes left in DMA buffer (0=64k)
         */
+       lock_kernel();
        orig_jiffies = jiffies;
        while (info->xmit.head != info->xmit.tail || /* More in send queue */
               (*info->ostatusadr & 0x007f) ||  /* more in FIFO */
                        curr_time_usec - info->last_tx_active_usec;
        }
        set_current_state(TASK_RUNNING);
+       unlock_kernel();
 }
 
 /*
 
                        tty_wait_until_sent(tty, 0);
                        send_break(info, arg ? arg*(HZ/10) : HZ/4);
                        return 0;
-               case TIOCGSOFTCAR:
-                       error = put_user(C_CLOCAL(tty) ? 1 : 0,
-                                   (unsigned long *) arg);
-                       if (error)
-                               return error;
-                       return 0;
-               case TIOCSSOFTCAR:
-                       get_user(arg, (unsigned long *) arg);
-                       tty->termios->c_cflag =
-                               ((tty->termios->c_cflag & ~CLOCAL) |
-                                (arg ? CLOCAL : 0));
-                       return 0;
                case TIOCGSERIAL:
                        if (access_ok(VERIFY_WRITE, (void *) arg,
                                                sizeof(struct serial_struct)))
        } else
 #endif
        shutdown(info);
-       if (tty->driver->flush_buffer)
-               tty->driver->flush_buffer(tty);
+       mcfrs_flush_buffer(tty);
        tty_ldisc_flush(tty);
        
        tty->closing = 0;
         * Note: we have to use pretty tight timings here to satisfy
         * the NIST-PCTS.
         */
+       lock_kernel();
+
        fifo_time = (MCF5272_FIFO_SIZE * HZ * 10) / info->baud;
        char_time = fifo_time / 5;
        if (char_time == 0)
                if (timeout && time_after(jiffies, orig_jiffies + timeout))
                        break;
        }
+       unlock_kernel();
 #else
        /*
         * For the other coldfire models, assume all data has been sent
 
 {
        unsigned int val;
 
+       /* FIXME: Locking needed ? */
        if (mctrl & TIOCM_RTS) {
                val = readl(port->membase + UART_RTS_CR);
                writel(val | RTS_CR_RTS, port->membase + UART_RTS_CR);