1 files changed, 93 insertions, 79 deletions

diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index 2dafc2da0648..e2f731b70763 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -850,7 +850,7 @@ MODULE_DEVICE_TABLE(pci, cy_pci_dev_id);
 #endif
 
 static void cy_start(struct tty_struct *);
-static void set_line_char(struct cyclades_port *);
+static void cy_set_line_char(struct cyclades_port *, struct tty_struct *);
 static int cyz_issue_cmd(struct cyclades_card *, __u32, __u8, __u32);
 #ifdef CONFIG_ISA
 static unsigned detect_isa_irq(void __iomem *);
@@ -1011,8 +1011,9 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
         save_car = readb(base_addr + (CyCAR << index));
         cy_writeb(base_addr + (CyCAR << index), save_xir);
 
+        tty = tty_port_tty_get(&info->port);
         /* if there is nowhere to put the data, discard it */
-        if (info->port.tty == NULL) {
+        if (tty == NULL) {
                 if ((readb(base_addr + (CyRIVR << index)) & CyIVRMask) ==
                                 CyIVRRxEx) {    /* exception */
                         data = readb(base_addr + (CyRDSR << index));
@@ -1024,7 +1025,6 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
                 goto end;
         }
         /* there is an open port for this data */
-        tty = info->port.tty;
         if ((readb(base_addr + (CyRIVR << index)) & CyIVRMask) ==
                         CyIVRRxEx) {    /* exception */
                 data = readb(base_addr + (CyRDSR << index));
@@ -1041,6 +1041,7 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
 
                 if (data & info->ignore_status_mask) {
                         info->icount.rx++;
+                        tty_kref_put(tty);
                         return;
                 }
                 if (tty_buffer_request_room(tty, 1)) {
@@ -1121,6 +1122,7 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
                 info->idle_stats.recv_idle = jiffies;
         }
         tty_schedule_flip(tty);
+        tty_kref_put(tty);
 end:
         /* end of service */
         cy_writeb(base_addr + (CyRIR << index), save_xir & 0x3f);
@@ -1131,6 +1133,7 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip,
                 void __iomem *base_addr)
 {
         struct cyclades_port *info;
+        struct tty_struct *tty;
         int char_count, index = cinfo->bus_index;
         u8 save_xir, channel, save_car, outch;
 
@@ -1154,7 +1157,8 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip,
                 goto end;
         }
         info = &cinfo->ports[channel + chip * 4];
-        if (info->port.tty == NULL) {
+        tty = tty_port_tty_get(&info->port);
+        if (tty == NULL) {
                 cy_writeb(base_addr + (CySRER << index),
                           readb(base_addr + (CySRER << index)) & ~CyTxRdy);
                 goto end;
@@ -1205,7 +1209,7 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip,
                                         ~CyTxRdy);
                         goto done;
                 }
-                if (info->port.tty->stopped || info->port.tty->hw_stopped) {
+                if (tty->stopped || tty->hw_stopped) {
                         cy_writeb(base_addr + (CySRER << index),
                                 readb(base_addr + (CySRER << index)) &
                                         ~CyTxRdy);
@@ -1241,7 +1245,8 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip,
         }
 
 done:
-        tty_wakeup(info->port.tty);
+        tty_wakeup(tty);
+        tty_kref_put(tty);
 end:
         /* end of service */
         cy_writeb(base_addr + (CyTIR << index), save_xir & 0x3f);
@@ -1252,6 +1257,7 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip,
                 void __iomem *base_addr)
 {
         struct cyclades_port *info;
+        struct tty_struct *tty;
         int index = cinfo->bus_index;
         u8 save_xir, channel, save_car, mdm_change, mdm_status;
 
@@ -1265,7 +1271,8 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip,
         mdm_change = readb(base_addr + (CyMISR << index));
         mdm_status = readb(base_addr + (CyMSVR1 << index));
 
-        if (!info->port.tty)
+        tty = tty_port_tty_get(&info->port);
+        if (!tty)
                 goto end;
 
         if (mdm_change & CyANY_DELTA) {
@@ -1284,27 +1291,27 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip,
 
         if ((mdm_change & CyDCD) && (info->port.flags & ASYNC_CHECK_CD)) {
                 if (!(mdm_status & CyDCD)) {
-                        tty_hangup(info->port.tty);
+                        tty_hangup(tty);
                         info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
                 }
                 wake_up_interruptible(&info->port.open_wait);
         }
         if ((mdm_change & CyCTS) && (info->port.flags & ASYNC_CTS_FLOW)) {
-                if (info->port.tty->hw_stopped) {
+                if (tty->hw_stopped) {
                         if (mdm_status & CyCTS) {
                                 /* cy_start isn't used
                                    because... !!! */
-                                info->port.tty->hw_stopped = 0;
+                                tty->hw_stopped = 0;
                                 cy_writeb(base_addr + (CySRER << index),
                                         readb(base_addr + (CySRER << index)) |
                                                 CyTxRdy);
-                                tty_wakeup(info->port.tty);
+                                tty_wakeup(tty);
                         }
                 } else {
                         if (!(mdm_status & CyCTS)) {
                                 /* cy_stop isn't used
                                    because ... !!! */
-                                info->port.tty->hw_stopped = 1;
+                                tty->hw_stopped = 1;
                                 cy_writeb(base_addr + (CySRER << index),
                                         readb(base_addr + (CySRER << index)) &
                                                 ~CyTxRdy);
@@ -1315,6 +1322,7 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip,
         }
         if (mdm_change & CyRI) {
         }*/
+        tty_kref_put(tty);
 end:
         /* end of service */
         cy_writeb(base_addr + (CyMIR << index), save_xir & 0x3f);
@@ -1449,11 +1457,10 @@ cyz_issue_cmd(struct cyclades_card *cinfo,
         return 0;
 }                               /* cyz_issue_cmd */
 
-static void cyz_handle_rx(struct cyclades_port *info,
+static void cyz_handle_rx(struct cyclades_port *info, struct tty_struct *tty,
                 struct BUF_CTRL __iomem *buf_ctrl)
 {
         struct cyclades_card *cinfo = info->card;
-        struct tty_struct *tty = info->port.tty;
         unsigned int char_count;
         int len;
 #ifdef BLOCKMOVE
@@ -1542,11 +1549,10 @@ static void cyz_handle_rx(struct cyclades_port *info,
         }
 }
 
-static void cyz_handle_tx(struct cyclades_port *info,
+static void cyz_handle_tx(struct cyclades_port *info, struct tty_struct *tty,
                 struct BUF_CTRL __iomem *buf_ctrl)
 {
         struct cyclades_card *cinfo = info->card;
-        struct tty_struct *tty = info->port.tty;
         u8 data;
         unsigned int char_count;
 #ifdef BLOCKMOVE
@@ -1642,7 +1648,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
                 special_count = 0;
                 delta_count = 0;
                 info = &cinfo->ports[channel];
-                tty = info->port.tty;
+                tty = tty_port_tty_get(&info->port);
                 if (tty == NULL)
                         continue;
 
@@ -1674,7 +1680,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
                                                 C_RS_DCD) {
                                         wake_up_interruptible(&info->port.open_wait);
                                 } else {
-                                        tty_hangup(info->port.tty);
+                                        tty_hangup(tty);
                                         wake_up_interruptible(&info->port.open_wait);
                                         info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
                                 }
@@ -1706,7 +1712,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
                         printk(KERN_DEBUG "cyz_interrupt: rcvd intr, card %d, "
                                         "port %ld\n", info->card, channel);
 #endif
-                        cyz_handle_rx(info, buf_ctrl);
+                        cyz_handle_rx(info, tty, buf_ctrl);
                         break;
                 case C_CM_TXBEMPTY:
                 case C_CM_TXLOWWM:
@@ -1716,7 +1722,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
                         printk(KERN_DEBUG "cyz_interrupt: xmit intr, card %d, "
                                         "port %ld\n", info->card, channel);
 #endif
-                        cyz_handle_tx(info, buf_ctrl);
+                        cyz_handle_tx(info, tty, buf_ctrl);
                         break;
 #endif                          /* CONFIG_CYZ_INTR */
                 case C_CM_FATAL:
@@ -1729,6 +1735,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
                         wake_up_interruptible(&info->delta_msr_wait);
                 if (special_count)
                         tty_schedule_flip(tty);
+                tty_kref_put(tty);
         }
 }
 
@@ -1774,7 +1781,6 @@ static void cyz_poll(unsigned long arg)
 {
         struct cyclades_card *cinfo;
         struct cyclades_port *info;
-        struct tty_struct *tty;
         struct FIRM_ID __iomem *firm_id;
         struct ZFW_CTRL __iomem *zfw_ctrl;
         struct BUF_CTRL __iomem *buf_ctrl;
@@ -1802,13 +1808,19 @@ static void cyz_poll(unsigned long arg)
                 cyz_handle_cmd(cinfo);
 
                 for (port = 0; port < cinfo->nports; port++) {
+                        struct tty_struct *tty;
+
                         info = &cinfo->ports[port];
-                        tty = info->port.tty;
                         buf_ctrl = &(zfw_ctrl->buf_ctrl[port]);
 
+                        tty = tty_port_tty_get(&info->port);
+                        /* OK to pass NULL to the handle functions below.
+                           They need to drop the data in that case. */
+
                         if (!info->throttle)
-                                cyz_handle_rx(info, buf_ctrl);
-                        cyz_handle_tx(info, buf_ctrl);
+                                cyz_handle_rx(info, tty, buf_ctrl);
+                        cyz_handle_tx(info, tty, buf_ctrl);
+                        tty_kref_put(tty);
                 }
                 /* poll every 'cyz_polling_cycle' period */
                 expires = jiffies + cyz_polling_cycle;
@@ -1824,7 +1836,7 @@ static void cyz_poll(unsigned long arg)
 /* This is called whenever a port becomes active;
    interrupts are enabled and DTR & RTS are turned on.
  */
-static int startup(struct cyclades_port *info)
+static int cy_startup(struct cyclades_port *info, struct tty_struct *tty)
 {
         struct cyclades_card *card;
         unsigned long flags;
@@ -1848,8 +1860,7 @@ static int startup(struct cyclades_port *info)
         }
 
         if (!info->type) {
-                if (info->port.tty)
-                        set_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                set_bit(TTY_IO_ERROR, &tty->flags);
                 free_page(page);
                 goto errout;
         }
@@ -1861,7 +1872,7 @@ static int startup(struct cyclades_port *info)
 
         spin_unlock_irqrestore(&card->card_lock, flags);
 
-        set_line_char(info);
+        cy_set_line_char(info, tty);
 
         if (!cy_is_Z(card)) {
                 chip = channel >> 2;
@@ -1900,8 +1911,7 @@ static int startup(struct cyclades_port *info)
                         readb(base_addr + (CySRER << index)) | CyRxData);
                 info->port.flags |= ASYNC_INITIALIZED;
 
-                if (info->port.tty)
-                        clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                clear_bit(TTY_IO_ERROR, &tty->flags);
                 info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
                 info->breakon = info->breakoff = 0;
                 memset((char *)&info->idle_stats, 0, sizeof(info->idle_stats));
@@ -1984,8 +1994,7 @@ static int startup(struct cyclades_port *info)
                 /* enable send, recv, modem !!! */
 
                 info->port.flags |= ASYNC_INITIALIZED;
-                if (info->port.tty)
-                        clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                clear_bit(TTY_IO_ERROR, &tty->flags);
                 info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
                 info->breakon = info->breakoff = 0;
                 memset((char *)&info->idle_stats, 0, sizeof(info->idle_stats));
@@ -2047,7 +2056,7 @@ static void start_xmit(struct cyclades_port *info)
  * This routine shuts down a serial port; interrupts are disabled,
  * and DTR is dropped if the hangup on close termio flag is on.
  */
-static void shutdown(struct cyclades_port *info)
+static void cy_shutdown(struct cyclades_port *info, struct tty_struct *tty)
 {
         struct cyclades_card *card;
         unsigned long flags;
@@ -2083,7 +2092,7 @@ static void shutdown(struct cyclades_port *info)
                         free_page((unsigned long)temp);
                 }
                 cy_writeb(base_addr + (CyCAR << index), (u_char) channel);
-                if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL)) {
+                if (tty->termios->c_cflag & HUPCL) {
                         cy_writeb(base_addr + (CyMSVR1 << index), ~CyRTS);
                         cy_writeb(base_addr + (CyMSVR2 << index), ~CyDTR);
 #ifdef CY_DEBUG_DTR
@@ -2097,8 +2106,7 @@ static void shutdown(struct cyclades_port *info)
                 /* it may be appropriate to clear _XMIT at
                    some later date (after testing)!!! */
 
-                if (info->port.tty)
-                        set_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                set_bit(TTY_IO_ERROR, &tty->flags);
                 info->port.flags &= ~ASYNC_INITIALIZED;
                 spin_unlock_irqrestore(&card->card_lock, flags);
         } else {
@@ -2132,7 +2140,7 @@ static void shutdown(struct cyclades_port *info)
                         free_page((unsigned long)temp);
                 }
 
-                if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL)) {
+                if (tty->termios->c_cflag & HUPCL) {
                         cy_writel(&ch_ctrl[channel].rs_control,
                                 (__u32)(readl(&ch_ctrl[channel].rs_control) &
                                         ~(C_RS_RTS | C_RS_DTR)));
@@ -2147,8 +2155,7 @@ static void shutdown(struct cyclades_port *info)
 #endif
                 }
 
-                if (info->port.tty)
-                        set_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                set_bit(TTY_IO_ERROR, &tty->flags);
                 info->port.flags &= ~ASYNC_INITIALIZED;
 
                 spin_unlock_irqrestore(&card->card_lock, flags);
@@ -2436,7 +2443,6 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
         printk(KERN_DEBUG "cyc:cy_open ttyC%d\n", info->line);
 #endif
         tty->driver_data = info;
-        info->port.tty = tty;
         if (serial_paranoia_check(info, tty->name, "cy_open"))
                 return -ENODEV;
 
@@ -2462,7 +2468,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
         /*
          * Start up serial port
          */
-        retval = startup(info);
+        retval = cy_startup(info, tty);
         if (retval)
                 return retval;
 
@@ -2476,6 +2482,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
         }
 
         info->throttle = 0;
+        tty_port_tty_set(&info->port, tty);
 
 #ifdef CY_DEBUG_OPEN
         printk(KERN_DEBUG "cyc:cy_open done\n");
@@ -2705,13 +2712,13 @@ static void cy_close(struct tty_struct *tty, struct file *filp)
         }
 
         spin_unlock_irqrestore(&card->card_lock, flags);
-        shutdown(info);
+        cy_shutdown(info, tty);
         cy_flush_buffer(tty);
         tty_ldisc_flush(tty);
         spin_lock_irqsave(&card->card_lock, flags);
 
         tty->closing = 0;
-        info->port.tty = NULL;
+        tty_port_tty_set(&info->port, NULL);
         if (info->port.blocked_open) {
                 spin_unlock_irqrestore(&card->card_lock, flags);
                 if (info->port.close_delay) {
@@ -2957,7 +2964,7 @@ static void cyy_baud_calc(struct cyclades_port *info, __u32 baud)
  * This routine finds or computes the various line characteristics.
  * It used to be called config_setup
  */
-static void set_line_char(struct cyclades_port *info)
+static void cy_set_line_char(struct cyclades_port *info, struct tty_struct *tty)
 {
         struct cyclades_card *card;
         unsigned long flags;
@@ -2967,28 +2974,26 @@ static void set_line_char(struct cyclades_port *info)
         int baud, baud_rate = 0;
         int i;
 
-        if (!info->port.tty || !info->port.tty->termios)
+        if (!tty->termios) /* XXX can this happen at all? */
                 return;
 
         if (info->line == -1)
                 return;
 
-        cflag = info->port.tty->termios->c_cflag;
-        iflag = info->port.tty->termios->c_iflag;
+        cflag = tty->termios->c_cflag;
+        iflag = tty->termios->c_iflag;
 
         /*
          * Set up the tty->alt_speed kludge
          */
-        if (info->port.tty) {
-                if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
-                        info->port.tty->alt_speed = 57600;
-                if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
-                        info->port.tty->alt_speed = 115200;
-                if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
-                        info->port.tty->alt_speed = 230400;
-                if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
-                        info->port.tty->alt_speed = 460800;
-        }
+        if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
+                tty->alt_speed = 57600;
+        if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
+                tty->alt_speed = 115200;
+        if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
+                tty->alt_speed = 230400;
+        if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
+                tty->alt_speed = 460800;
 
         card = info->card;
         channel = info->line - card->first_line;
@@ -2998,7 +3003,7 @@ static void set_line_char(struct cyclades_port *info)
                 index = card->bus_index;
 
                 /* baud rate */
-                baud = tty_get_baud_rate(info->port.tty);
+                baud = tty_get_baud_rate(tty);
                 if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                 ASYNC_SPD_CUST) {
                         if (info->custom_divisor)
@@ -3123,9 +3128,8 @@ static void set_line_char(struct cyclades_port *info)
 
                 /* set line characteristics  according configuration */
 
-                cy_writeb(base_addr + (CySCHR1 << index),
-                          START_CHAR(info->port.tty));
-                cy_writeb(base_addr + (CySCHR2 << index), STOP_CHAR(info->port.tty));
+                cy_writeb(base_addr + (CySCHR1 << index), START_CHAR(tty));
+                cy_writeb(base_addr + (CySCHR2 << index), STOP_CHAR(tty));
                 cy_writeb(base_addr + (CyCOR1 << index), info->cor1);
                 cy_writeb(base_addr + (CyCOR2 << index), info->cor2);
                 cy_writeb(base_addr + (CyCOR3 << index), info->cor3);
@@ -3141,7 +3145,7 @@ static void set_line_char(struct cyclades_port *info)
                         (info->default_timeout ? info->default_timeout : 0x02));
                 /* 10ms rx timeout */
 
-                if (C_CLOCAL(info->port.tty)) {
+                if (C_CLOCAL(tty)) {
                         /* without modem intr */
                         cy_writeb(base_addr + (CySRER << index),
                                 readb(base_addr + (CySRER << index)) | CyMdmCh);
@@ -3204,8 +3208,7 @@ static void set_line_char(struct cyclades_port *info)
 #endif
                 }
 
-                if (info->port.tty)
-                        clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                clear_bit(TTY_IO_ERROR, &tty->flags);
                 spin_unlock_irqrestore(&card->card_lock, flags);
 
         } else {
@@ -3224,7 +3227,7 @@ static void set_line_char(struct cyclades_port *info)
                 ch_ctrl = &(zfw_ctrl->ch_ctrl[channel]);
 
                 /* baud rate */
-                baud = tty_get_baud_rate(info->port.tty);
+                baud = tty_get_baud_rate(tty);
                 if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                 ASYNC_SPD_CUST) {
                         if (info->custom_divisor)
@@ -3335,8 +3338,7 @@ static void set_line_char(struct cyclades_port *info)
                                 "was %x\n", info->line, retval);
                 }
 
-                if (info->port.tty)
-                        clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+                clear_bit(TTY_IO_ERROR, &tty->flags);
         }
 }                               /* set_line_char */
 
@@ -3365,7 +3367,7 @@ get_serial_info(struct cyclades_port *info,
 }                               /* get_serial_info */
 
 static int
-set_serial_info(struct cyclades_port *info,
+cy_set_serial_info(struct cyclades_port *info, struct tty_struct *tty,
                 struct serial_struct __user *new_info)
 {
         struct serial_struct new_serial;
@@ -3403,10 +3405,10 @@ set_serial_info(struct cyclades_port *info,
 
 check_and_exit:
         if (info->port.flags & ASYNC_INITIALIZED) {
-                set_line_char(info);
+                cy_set_line_char(info, tty);
                 return 0;
         } else {
-                return startup(info);
+                return cy_startup(info, tty);
         }
 }                               /* set_serial_info */
 
@@ -3955,7 +3957,7 @@ cy_ioctl(struct tty_struct *tty, struct file *file,
                 ret_val = get_serial_info(info, argp);
                 break;
         case TIOCSSERIAL:
-                ret_val = set_serial_info(info, argp);
+                ret_val = cy_set_serial_info(info, tty, argp);
                 break;
         case TIOCSERGETLSR:     /* Get line status register */
                 ret_val = get_lsr_info(info, argp);
@@ -4055,7 +4057,7 @@ static void cy_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
         printk(KERN_DEBUG "cyc:cy_set_termios ttyC%d\n", info->line);
 #endif
 
-        set_line_char(info);
+        cy_set_line_char(info, tty);
 
         if ((old_termios->c_cflag & CRTSCTS) &&
                         !(tty->termios->c_cflag & CRTSCTS)) {
@@ -4299,13 +4301,13 @@ static void cy_hangup(struct tty_struct *tty)
                 return;
 
         cy_flush_buffer(tty);
-        shutdown(info);
+        cy_shutdown(info, tty);
         info->port.count = 0;
 #ifdef CY_DEBUG_COUNT
         printk(KERN_DEBUG "cyc:cy_hangup (%d): setting count to 0\n",
                 current->pid);
 #endif
-        info->port.tty = NULL;
+        tty_port_tty_set(&info->port, NULL);
         info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
         wake_up_interruptible(&info->port.open_wait);
 }                               /* cy_hangup */
@@ -5191,18 +5193,30 @@ static int cyclades_proc_show(struct seq_file *m, void *v)
                 for (j = 0; j < cy_card[i].nports; j++) {
                         info = &cy_card[i].ports[j];
 
-                        if (info->port.count)
+                        if (info->port.count) {
+                                /* XXX is the ldisc num worth this? */
+                                struct tty_struct *tty;
+                                struct tty_ldisc *ld;
+                                int num = 0;
+                                tty = tty_port_tty_get(&info->port);
+                                if (tty) {
+                                        ld = tty_ldisc_ref(tty);
+                                        if (ld) {
+                                                num = ld->ops->num;
+                                                tty_ldisc_deref(ld);
+                                        }
+                                        tty_kref_put(tty);
+                                }
                                 seq_printf(m, "%3d %8lu %10lu %8lu "
-                                        "%10lu %8lu %9lu %6ld\n", info->line,
+                                        "%10lu %8lu %9lu %6d\n", info->line,
                                         (cur_jifs - info->idle_stats.in_use) /
                                         HZ, info->idle_stats.xmit_bytes,
                                         (cur_jifs - info->idle_stats.xmit_idle)/
                                         HZ, info->idle_stats.recv_bytes,
                                         (cur_jifs - info->idle_stats.recv_idle)/
                                         HZ, info->idle_stats.overruns,
-                                        /* FIXME: double check locking */
-                                        (long)info->port.tty->ldisc->ops->num);
-                        else
+                                        num);
+                        } else
                                 seq_printf(m, "%3d %8lu %10lu %8lu "
                                         "%10lu %8lu %9lu %6ld\n",
                                         info->line, 0L, 0L, 0L, 0L, 0L, 0L, 0L);