Char: moxa, merge 2 poll functions

- merge 2 timers into one -- one can handle the emptywait as good as the other
- merge 2 separated poll functions into one, this allows handle the actions
  directly and simplifies the code

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 141 insertions, 290 deletions

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index f737fbb8598c..a64707623e47 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -129,25 +129,22 @@ struct moxaq_str {
 
 struct moxa_port {
         struct moxa_board_conf *board;
+        struct tty_struct *tty;
+        void __iomem *tableAddr;
+
         int type;
         int close_delay;
         int count;
         int blocked_open;
         int asyncflags;
-        unsigned long statusflags;
-        struct tty_struct *tty;
         int cflag;
+        unsigned long statusflags;
         wait_queue_head_t open_wait;
         struct completion close_wait;
 
-        struct timer_list emptyTimer;
-
-        char lineCtrl;
-        void __iomem *tableAddr;
-        char DCDState;
-        char lowChkFlag;
-
-        ushort breakCnt;
+        u8 DCDState;
+        u8 lineCtrl;
+        u8 lowChkFlag;
 };
 
 struct mon_str {
@@ -169,6 +166,7 @@ struct mon_str {
 static int ttymajor = MOXAMAJOR;
 static struct mon_str moxaLog;
 static unsigned int moxaFuncTout = HZ / 2;
+static unsigned int moxaLowWaterChk;
 /* Variables for insmod */
 #ifdef MODULE
 static unsigned long baseaddr[MAX_BOARDS];
@@ -214,13 +212,10 @@ static void moxa_set_tty_param(struct tty_struct *, struct ktermios *);
 static int moxa_block_till_ready(struct tty_struct *, struct file *,
                             struct moxa_port *);
 static void moxa_setup_empty_event(struct tty_struct *);
-static void moxa_check_xmit_empty(unsigned long);
 static void moxa_shut_down(struct moxa_port *);
-static void moxa_receive_data(struct moxa_port *);
 /*
  * moxa board interface functions:
  */
-static int MoxaDriverPoll(void);
 static void MoxaPortEnable(struct moxa_port *);
 static void MoxaPortDisable(struct moxa_port *);
 static int MoxaPortSetTermio(struct moxa_port *, struct ktermios *, speed_t);
@@ -228,17 +223,14 @@ static int MoxaPortGetLineOut(struct moxa_port *, int *, int *);
 static void MoxaPortLineCtrl(struct moxa_port *, int, int);
 static void MoxaPortFlowCtrl(struct moxa_port *, int, int, int, int, int);
 static int MoxaPortLineStatus(struct moxa_port *);
-static int MoxaPortDCDChange(struct moxa_port *);
-static int MoxaPortDCDON(struct moxa_port *);
 static void MoxaPortFlushData(struct moxa_port *, int);
 static int MoxaPortWriteData(struct moxa_port *, unsigned char *, int);
-static int MoxaPortReadData(struct moxa_port *, struct tty_struct *tty);
+static int MoxaPortReadData(struct moxa_port *);
 static int MoxaPortTxQueue(struct moxa_port *);
 static int MoxaPortRxQueue(struct moxa_port *);
 static int MoxaPortTxFree(struct moxa_port *);
 static void MoxaPortTxDisable(struct moxa_port *);
 static void MoxaPortTxEnable(struct moxa_port *);
-static int MoxaPortResetBrkCnt(struct moxa_port *);
 static int moxa_get_serial_info(struct moxa_port *, struct serial_struct __user *);
 static int moxa_set_serial_info(struct moxa_port *, struct serial_struct __user *);
 static void MoxaSetFifo(struct moxa_port *port, int enable);
@@ -265,6 +257,20 @@ static void moxafunc(void __iomem *ofsAddr, int cmd, ushort arg)
         moxa_wait_finish(ofsAddr);
 }
 
+static void moxa_low_water_check(void __iomem *ofsAddr)
+{
+        u16 rptr, wptr, mask, len;
+
+        if (readb(ofsAddr + FlagStat) & Xoff_state) {
+                rptr = readw(ofsAddr + RXrptr);
+                wptr = readw(ofsAddr + RXwptr);
+                mask = readw(ofsAddr + RX_mask);
+                len = (wptr - rptr) & mask;
+                if (len <= Low_water)
+                        moxafunc(ofsAddr, FC_SendXon, 0);
+        }
+}
+
 /*
  * TTY operations
  */
@@ -812,9 +818,6 @@ static int moxa_init_board(struct moxa_board_conf *brd, struct device *dev)
                 p->cflag = B9600 | CS8 | CREAD | CLOCAL | HUPCL;
                 init_waitqueue_head(&p->open_wait);
                 init_completion(&p->close_wait);
-
-                setup_timer(&p->emptyTimer, moxa_check_xmit_empty,
-                                (unsigned long)p);
         }
 
         switch (brd->boardType) {
@@ -857,12 +860,9 @@ err:
 
 static void moxa_board_deinit(struct moxa_board_conf *brd)
 {
-        unsigned int i;
-
+        spin_lock_bh(&moxa_lock);
         brd->ready = 0;
-        for (i = 0; i < MAX_PORTS_PER_BOARD; i++)
-                del_timer_sync(&brd->ports[i].emptyTimer);
-
+        spin_unlock_bh(&moxa_lock);
         iounmap(brd->basemem);
         brd->basemem = NULL;
         kfree(brd->ports);
@@ -1135,7 +1135,6 @@ static void moxa_close(struct tty_struct *tty, struct file *filp)
         if (ch->asyncflags & ASYNC_INITIALIZED) {
                 moxa_setup_empty_event(tty);
                 tty_wait_until_sent(tty, 30 * HZ);      /* 30 seconds timeout */
-                del_timer_sync(&ch->emptyTimer);
         }
         moxa_shut_down(ch);
         MoxaPortFlushData(ch, 2);
@@ -1160,15 +1159,14 @@ static int moxa_write(struct tty_struct *tty,
                       const unsigned char *buf, int count)
 {
         struct moxa_port *ch = tty->driver_data;
-        unsigned long flags;
         int len;
 
         if (ch == NULL)
                 return 0;
 
-        spin_lock_irqsave(&moxa_lock, flags);
+        spin_lock_bh(&moxa_lock);
         len = MoxaPortWriteData(ch, (unsigned char *) buf, count);
-        spin_unlock_irqrestore(&moxa_lock, flags);
+        spin_unlock_bh(&moxa_lock);
 
         /*********************************************
         if ( !(ch->statusflags & LOWWAIT) &&
@@ -1236,13 +1234,12 @@ static void moxa_flush_chars(struct tty_struct *tty)
 static void moxa_put_char(struct tty_struct *tty, unsigned char c)
 {
         struct moxa_port *ch = tty->driver_data;
-        unsigned long flags;
 
         if (ch == NULL)
                 return;
-        spin_lock_irqsave(&moxa_lock, flags);
+        spin_lock_bh(&moxa_lock);
         MoxaPortWriteData(ch, &c, 1);
-        spin_unlock_irqrestore(&moxa_lock, flags);
+        spin_unlock_bh(&moxa_lock);
         /************************************************
         if ( !(ch->statusflags & LOWWAIT) && (MoxaPortTxFree(port) <= 100) )
         *************************************************/
@@ -1360,58 +1357,110 @@ static void moxa_hangup(struct tty_struct *tty)
         wake_up_interruptible(&ch->open_wait);
 }
 
-static void moxa_poll(unsigned long ignored)
+static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
 {
-        struct moxa_port *ch;
-        struct tty_struct *tty;
-        unsigned int card;
-        int i;
+        dcd = !!dcd;
 
-        del_timer(&moxaTimer);
+        if ((dcd != p->DCDState) && p->tty && C_CLOCAL(p->tty)) {
+                if (!dcd) {
+                        tty_hangup(p->tty);
+                        p->asyncflags &= ~ASYNC_NORMAL_ACTIVE;
+                }
+                wake_up_interruptible(&p->open_wait);
+        }
+        p->DCDState = dcd;
+}
 
-        if (MoxaDriverPoll() < 0) {
-                mod_timer(&moxaTimer, jiffies + HZ / 50);
-                return;
+static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
+                u16 __iomem *ip)
+{
+        struct tty_struct *tty = p->tty;
+        void __iomem *ofsAddr;
+        unsigned int inited = p->asyncflags & ASYNC_INITIALIZED;
+        u16 intr;
+
+        if (tty) {
+                if ((p->statusflags & EMPTYWAIT) &&
+                                MoxaPortTxQueue(p) == 0) {
+                        p->statusflags &= ~EMPTYWAIT;
+                        tty_wakeup(tty);
+                }
+                if ((p->statusflags & LOWWAIT) && !tty->stopped &&
+                                MoxaPortTxQueue(p) <= WAKEUP_CHARS) {
+                        p->statusflags &= ~LOWWAIT;
+                        tty_wakeup(tty);
+                }
+
+                if (inited && !(p->statusflags & THROTTLE) &&
+                                MoxaPortRxQueue(p) > 0) { /* RX */
+                        MoxaPortReadData(p);
+                        tty_schedule_flip(tty);
+                }
+        } else {
+                p->statusflags &= ~EMPTYWAIT;
+                MoxaPortFlushData(p, 0); /* flush RX */
         }
 
+        if (!handle) /* nothing else to do */
+                return 0;
+
+        intr = readw(ip); /* port irq status */
+        if (intr == 0)
+                return 0;
+
+        writew(0, ip); /* ACK port */
+        ofsAddr = p->tableAddr;
+        if (intr & IntrTx) /* disable tx intr */
+                writew(readw(ofsAddr + HostStat) & ~WakeupTx,
+                                ofsAddr + HostStat);
+
+        if (!inited)
+                return 0;
+
+        if (tty && (intr & IntrBreak) && !I_IGNBRK(tty)) { /* BREAK */
+                tty_insert_flip_char(tty, 0, TTY_BREAK);
+                tty_schedule_flip(tty);
+        }
+
+        if (intr & IntrLine)
+                moxa_new_dcdstate(p, readb(ofsAddr + FlagStat) & DCD_state);
+
+        return 0;
+}
+
+static void moxa_poll(unsigned long ignored)
+{
+        struct moxa_board_conf *brd;
+        u16 __iomem *ip;
+        unsigned int card, port;
+
+        spin_lock(&moxa_lock);
         for (card = 0; card < MAX_BOARDS; card++) {
-                if (!moxa_boards[card].ready)
+                brd = &moxa_boards[card];
+                if (!brd->ready)
                         continue;
-                ch = moxa_boards[card].ports;
-                for (i = 0; i < moxa_boards[card].numPorts; i++, ch++) {
-                        if ((ch->asyncflags & ASYNC_INITIALIZED) == 0)
-                                continue;
-                        if (!(ch->statusflags & THROTTLE) &&
-                            (MoxaPortRxQueue(ch) > 0))
-                                moxa_receive_data(ch);
-                        tty = ch->tty;
-                        if (tty == NULL)
-                                continue;
-                        if (ch->statusflags & LOWWAIT) {
-                                if (MoxaPortTxQueue(ch) <= WAKEUP_CHARS) {
-                                        if (!tty->stopped) {
-                                                ch->statusflags &= ~LOWWAIT;
-                                                tty_wakeup(tty);
-                                        }
-                                }
-                        }
-                        if (!I_IGNBRK(tty) && (MoxaPortResetBrkCnt(ch) > 0)) {
-                                tty_insert_flip_char(tty, 0, TTY_BREAK);
-                                tty_schedule_flip(tty);
-                        }
-                        if (MoxaPortDCDChange(ch)) {
-                                if (ch->asyncflags & ASYNC_CHECK_CD) {
-                                        if (MoxaPortDCDON(ch))
-                                                wake_up_interruptible(&ch->open_wait);
-                                        else {
-                                                tty_hangup(tty);
-                                                wake_up_interruptible(&ch->open_wait);
-                                                ch->asyncflags &= ~ASYNC_NORMAL_ACTIVE;
-                                        }
+
+                ip = NULL;
+                if (readb(brd->intPend) == 0xff)
+                        ip = brd->intTable + readb(brd->intNdx);
+
+                for (port = 0; port < brd->numPorts; port++)
+                        moxa_poll_port(&brd->ports[port], !!ip, ip + port);
+
+                if (ip)
+                        writeb(0, brd->intPend); /* ACK */
+
+                if (moxaLowWaterChk) {
+                        struct moxa_port *p = brd->ports;
+                        for (port = 0; port < brd->numPorts; port++, p++)
+                                if (p->lowChkFlag) {
+                                        p->lowChkFlag = 0;
+                                        moxa_low_water_check(p->tableAddr);
                                 }
-                        }
                 }
         }
+        moxaLowWaterChk = 0;
+        spin_unlock(&moxa_lock);
 
         mod_timer(&moxaTimer, jiffies + HZ / 50);
 }
@@ -1426,10 +1475,6 @@ static void moxa_set_tty_param(struct tty_struct *tty, struct ktermios *old_term
 
         ch = (struct moxa_port *) tty->driver_data;
         ts = tty->termios;
-        if (ts->c_cflag & CLOCAL)
-                ch->asyncflags &= ~ASYNC_CHECK_CD;
-        else
-                ch->asyncflags |= ASYNC_CHECK_CD;
         rts = cts = txflow = rxflow = xany = 0;
         if (ts->c_cflag & CRTSCTS)
                 rts = cts = 1;
@@ -1454,7 +1499,6 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
                             struct moxa_port *ch)
 {
         DECLARE_WAITQUEUE(wait,current);
-        unsigned long flags;
         int retval;
         int do_clocal = C_CLOCAL(tty);
 
@@ -1489,11 +1533,11 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
         add_wait_queue(&ch->open_wait, &wait);
         pr_debug("block_til_ready before block: ttys%d, count = %d\n",
                 tty->index, ch->count);
-        spin_lock_irqsave(&moxa_lock, flags);
+        spin_lock_bh(&moxa_lock);
         if (!tty_hung_up_p(filp))
                 ch->count--;
         ch->blocked_open++;
-        spin_unlock_irqrestore(&moxa_lock, flags);
+        spin_unlock_bh(&moxa_lock);
 
         while (1) {
                 set_current_state(TASK_INTERRUPTIBLE);
@@ -1510,7 +1554,7 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
                         break;
                 }
                 if (!(ch->asyncflags & ASYNC_CLOSING) && (do_clocal ||
-                                                MoxaPortDCDON(ch)))
+                                ch->DCDState))
                         break;
 
                 if (signal_pending(current)) {
@@ -1522,11 +1566,11 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
         set_current_state(TASK_RUNNING);
         remove_wait_queue(&ch->open_wait, &wait);
 
-        spin_lock_irqsave(&moxa_lock, flags);
+        spin_lock_bh(&moxa_lock);
         if (!tty_hung_up_p(filp))
                 ch->count++;
         ch->blocked_open--;
-        spin_unlock_irqrestore(&moxa_lock, flags);
+        spin_unlock_bh(&moxa_lock);
         pr_debug("block_til_ready after blocking: ttys%d, count = %d\n",
                 tty->index, ch->count);
         if (retval)
@@ -1539,28 +1583,10 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
 static void moxa_setup_empty_event(struct tty_struct *tty)
 {
         struct moxa_port *ch = tty->driver_data;
-        unsigned long flags;
 
-        spin_lock_irqsave(&moxa_lock, flags);
+        spin_lock_bh(&moxa_lock);
         ch->statusflags |= EMPTYWAIT;
-        mod_timer(&ch->emptyTimer, jiffies + HZ);
-        spin_unlock_irqrestore(&moxa_lock, flags);
-}
-
-static void moxa_check_xmit_empty(unsigned long data)
-{
-        struct moxa_port *ch;
-
-        ch = (struct moxa_port *) data;
-        if (ch->tty && (ch->statusflags & EMPTYWAIT)) {
-                if (MoxaPortTxQueue(ch) == 0) {
-                        ch->statusflags &= ~EMPTYWAIT;
-                        tty_wakeup(ch->tty);
-                        return;
-                }
-                mod_timer(&ch->emptyTimer, round_jiffies(jiffies + HZ));
-        } else
-                ch->statusflags &= ~EMPTYWAIT;
+        spin_unlock_bh(&moxa_lock);
 }
 
 static void moxa_shut_down(struct moxa_port *ch)
@@ -1583,43 +1609,8 @@ static void moxa_shut_down(struct moxa_port *ch)
         ch->asyncflags &= ~ASYNC_INITIALIZED;
 }
 
-static void moxa_receive_data(struct moxa_port *ch)
-{
-        struct tty_struct *tp;
-        struct ktermios *ts;
-        unsigned long flags;
-
-        ts = NULL;
-        tp = ch->tty;
-        if (tp)
-                ts = tp->termios;
-        /**************************************************
-        if ( !tp || !ts || !(ts->c_cflag & CREAD) ) {
-        *****************************************************/
-        if (!tp || !ts) {
-                MoxaPortFlushData(ch, 0);
-                return;
-        }
-        spin_lock_irqsave(&moxa_lock, flags);
-        MoxaPortReadData(ch, tp);
-        spin_unlock_irqrestore(&moxa_lock, flags);
-        tty_schedule_flip(tp);
-}
-
-/*
- *    Query
- */
-
-#define         DCD_changed     0x01
-#define         DCD_oldstate    0x80
-
-static int moxaLowWaterChk;
-
-static void moxa_low_water_check(void __iomem *);
-
 /*****************************************************************************
  *      Driver level functions:                                              *
- *      3. MoxaDriverPoll(void);                                             *
  *****************************************************************************/
 
 static void MoxaPortFlushData(struct moxa_port *port, int mode)
@@ -1635,67 +1626,6 @@ static void MoxaPortFlushData(struct moxa_port *port, int mode)
         }
 }
 
-static int MoxaDriverPoll(void)
-{
-        struct moxa_board_conf *brd;
-        struct moxa_port *p;
-        void __iomem *ofsAddr;
-        void __iomem *ip;
-        unsigned int port, ports, card;
-        ushort temp;
-
-        for (card = 0; card < MAX_BOARDS; card++) {
-                brd = &moxa_boards[card];
-                if (brd->ready == 0)
-                        continue;
-                if ((ports = brd->numPorts) == 0)
-                        continue;
-                if (readb(brd->intPend) == 0xff) {
-                        ip = brd->intTable + readb(brd->intNdx);
-                        p = brd->ports;
-                        ports <<= 1;
-                        for (port = 0; port < ports; port += 2, p++) {
-                                temp = readw(ip + port);
-                                if (temp == 0)
-                                        continue;
-
-                                writew(0, ip + port);
-                                ofsAddr = p->tableAddr;
-                                if (temp & IntrTx)
-                                        writew(readw(ofsAddr + HostStat) &
-                                                ~WakeupTx, ofsAddr + HostStat);
-                                if (temp & IntrBreak)
-                                        p->breakCnt++;
-
-                                if (temp & IntrLine) {
-                                        if (readb(ofsAddr + FlagStat) & DCD_state) {
-                                                if ((p->DCDState & DCD_oldstate) == 0)
-                                                        p->DCDState = (DCD_oldstate |
-                                                                           DCD_changed);
-                                        } else {
-                                                if (p->DCDState & DCD_oldstate)
-                                                        p->DCDState = DCD_changed;
-                                        }
-                                }
-                        }
-                        writeb(0, brd->intPend);
-                }
-                if (moxaLowWaterChk) {
-                        p = brd->ports;
-                        for (port = 0; port < ports; port++, p++) {
-                                if (p->lowChkFlag) {
-                                        p->lowChkFlag = 0;
-                                        ofsAddr = p->tableAddr;
-                                        moxa_low_water_check(ofsAddr);
-                                }
-                        }
-                }
-        }
-        moxaLowWaterChk = 0;
-
-        return 0;
-}
-
 /*****************************************************************************
  *      Port level functions:                                                *
  *      2.  MoxaPortEnable(int port);                                        *
@@ -1707,8 +1637,6 @@ static int MoxaDriverPoll(void)
  *      10. MoxaPortLineCtrl(int port, int dtrState, int rtsState);          *
  *      11. MoxaPortFlowCtrl(int port, int rts, int cts, int rx, int tx,int xany);    *
  *      12. MoxaPortLineStatus(int port);                                    *
- *      13. MoxaPortDCDChange(int port);                                     *
- *      14. MoxaPortDCDON(int port);                                         *
  *      15. MoxaPortFlushData(int port, int mode);                           *
  *      16. MoxaPortWriteData(int port, unsigned char * buffer, int length); *
  *      17. MoxaPortReadData(int port, struct tty_struct *tty);              *
@@ -1755,14 +1683,6 @@ static int MoxaDriverPoll(void)
  *                      -ENOIOCTLCMD
  *
  *
- *      Function 3:     Moxa driver polling process routine.
- *      Syntax:
- *      int  MoxaDriverPoll(void);
- *
- *           return:    0       ; polling O.K.
- *                      -1      : no any Moxa card.             
- *
- *
  *      Function 6:     Enable this port to start Tx/Rx data.
  *      Syntax:
  *      void MoxaPortEnable(int port);
@@ -1853,25 +1773,6 @@ static int MoxaDriverPoll(void)
  *                      Bit 2 - DCD state (0: off, 1: on)
  *
  *
- *      Function 17:    Check the DCD state has changed since the last read
- *                      of this function.
- *      Syntax:
- *      int  MoxaPortDCDChange(int port);
- *           int port           : port number (0 - 127)
- *
- *           return:    0       : no changed
- *                      1       : DCD has changed
- *
- *
- *      Function 18:    Check ths current DCD state is ON or not.
- *      Syntax:
- *      int  MoxaPortDCDON(int port);
- *           int port           : port number (0 - 127)
- *
- *           return:    0       : DCD off
- *                      1       : DCD on
- *
- *
  *      Function 19:    Flush the Rx/Tx buffer data of this port.
  *      Syntax:
  *      void MoxaPortFlushData(int port, int mode);
@@ -1954,7 +1855,6 @@ static void MoxaPortEnable(struct moxa_port *port)
 
         ofsAddr = port->tableAddr;
         writew(lowwater, ofsAddr + Low_water);
-        port->breakCnt = 0;
         if (port->board->boardType == MOXA_BOARD_C320_ISA ||
             port->board->boardType == MOXA_BOARD_C320_PCI) {
                 moxafunc(ofsAddr, FC_SetBreakIrq, 0);
@@ -2123,37 +2023,11 @@ static int MoxaPortLineStatus(struct moxa_port *port)
                 val = readw(ofsAddr + FlagStat) >> 4;
         }
         val &= 0x0B;
-        if (val & 8) {
+        if (val & 8)
                 val |= 4;
-                if ((port->DCDState & DCD_oldstate) == 0)
-                        port->DCDState = (DCD_oldstate | DCD_changed);
-        } else {
-                if (port->DCDState & DCD_oldstate)
-                        port->DCDState = DCD_changed;
-        }
+        moxa_new_dcdstate(port, val & 8);
         val &= 7;
-        return (val);
-}
-
-static int MoxaPortDCDChange(struct moxa_port *port)
-{
-        int n;
-
-        n = port->DCDState;
-        port->DCDState &= ~DCD_changed;
-        n &= DCD_changed;
-        return (n);
-}
-
-static int MoxaPortDCDON(struct moxa_port *port)
-{
-        int n;
-
-        if (port->DCDState & DCD_oldstate)
-                n = 1;
-        else
-                n = 0;
-        return (n);
+        return val;
 }
 
 static int MoxaPortWriteData(struct moxa_port *port, unsigned char *buffer,
@@ -2221,8 +2095,9 @@ static int MoxaPortWriteData(struct moxa_port *port, unsigned char *buffer,
         return (total);
 }
 
-static int MoxaPortReadData(struct moxa_port *port, struct tty_struct *tty)
+static int MoxaPortReadData(struct moxa_port *port)
 {
+        struct tty_struct *tty = port->tty;
         register ushort head, pageofs;
         int i, count, cnt, len, total, remain;
         ushort tail, rx_mask, spage, epage;
@@ -2243,7 +2118,7 @@ static int MoxaPortReadData(struct moxa_port *port, struct tty_struct *tty)
 
         total = count;
         remain = count - total;
-        moxaLog.rxcnt[port->tty->index] += total;
+        moxaLog.rxcnt[tty->index] += total;
         count = total;
         if (spage == epage) {
                 bufhead = readw(ofsAddr + Ofs_rxb);
@@ -2341,15 +2216,6 @@ static void MoxaPortTxEnable(struct moxa_port *port)
         moxafunc(port->tableAddr, FC_SetXonState, Magic_code);
 }
 
-
-static int MoxaPortResetBrkCnt(struct moxa_port *port)
-{
-        ushort cnt;
-        cnt = port->breakCnt;
-        port->breakCnt = 0;
-        return (cnt);
-}
-
 static int moxa_get_serial_info(struct moxa_port *info,
                                 struct serial_struct __user *retinfo)
 {
@@ -2413,21 +2279,6 @@ static int moxa_set_serial_info(struct moxa_port *info,
  *      Static local functions:                                              *
  *****************************************************************************/
 
-static void moxa_low_water_check(void __iomem *ofsAddr)
-{
-        int len;
-        ushort rptr, wptr, mask;
-
-        if (readb(ofsAddr + FlagStat) & Xoff_state) {
-                rptr = readw(ofsAddr + RXrptr);
-                wptr = readw(ofsAddr + RXwptr);
-                mask = readw(ofsAddr + RX_mask);
-                len = (wptr - rptr) & mask;
-                if (len <= Low_water)
-                        moxafunc(ofsAddr, FC_SendXon, 0);
-        }
-}
-
 static void MoxaSetFifo(struct moxa_port *port, int enable)
 {
         void __iomem *ofsAddr = port->tableAddr;
diff --git a/drivers/char/moxa.h b/drivers/char/moxa.h
index 49e926dea195..0b1650621a04 100644
--- a/drivers/char/moxa.h
+++ b/drivers/char/moxa.h
@@ -165,11 +165,11 @@
 #define HostStat        0x08    /* IRQ flag and general flag      */
 #define FlagStat        0x0A
 #define FlowControl     0x0C    /* B7 B6 B5 B4 B3 B2 B1 B0              */
-                                        /*  x  x  x  x  |  |  |  |            */
-                                        /*              |  |  |  + CTS flow   */
-                                        /*              |  |  +--- RTS flow   */
-                                        /*              |  +------ TX Xon/Xoff */
-                                        /*              +--------- RX Xon/Xoff */
+                                /*  x  x  x  x  |  |  |  |            */
+                                /*              |  |  |  + CTS flow   */
+                                /*              |  |  +--- RTS flow   */
+                                /*              |  +------ TX Xon/Xoff */
+                                /*              +--------- RX Xon/Xoff */
 #define Break_cnt       0x0E    /* received break count   */
 #define CD180TXirq      0x10    /* if non-0: enable TX irq        */
 #define RX_mask         0x12