From d450b5a0196b6442cf3f29fc611d9c8daa56b559 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:39:58 +0100 Subject: tty: kref usage for isicom and moxa Rather than blindly keep taking krefs we reorder the code in a few places to pass the tty down to the right place (which is important as from the user side it is not the case that tty == port->tty in all situations). For the irq and related paths use the krefs to stop the tty being freed under us. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/char/moxa.c | 61 +++++++++++++++++++++++++++++++++-------------------- 1 file changed, 38 insertions(+), 23 deletions(-) (limited to 'drivers/char/moxa.c') diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c index d3d7864e0c1..5df4003ad87 100644 --- a/drivers/char/moxa.c +++ b/drivers/char/moxa.c @@ -205,7 +205,7 @@ static int moxa_tiocmset(struct tty_struct *tty, struct file *file, static void moxa_poll(unsigned long); static void moxa_set_tty_param(struct tty_struct *, struct ktermios *); static void moxa_setup_empty_event(struct tty_struct *); -static void moxa_shut_down(struct moxa_port *); +static void moxa_shut_down(struct tty_struct *); /* * moxa board interface functions: */ @@ -217,7 +217,7 @@ 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 void MoxaPortFlushData(struct moxa_port *, int); -static int MoxaPortWriteData(struct moxa_port *, const unsigned char *, int); +static int MoxaPortWriteData(struct tty_struct *, const unsigned char *, int); static int MoxaPortReadData(struct moxa_port *); static int MoxaPortTxQueue(struct moxa_port *); static int MoxaPortRxQueue(struct moxa_port *); @@ -332,6 +332,7 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, for (i = 0; i < MAX_BOARDS; i++) { p = moxa_boards[i].ports; for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) { + struct tty_struct *ttyp; memset(&tmp, 0, sizeof(tmp)); if (!moxa_boards[i].ready) goto copy; @@ -344,10 +345,12 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, if (status & 4) tmp.dcd = 1; - if (!p->port.tty || !p->port.tty->termios) + ttyp = tty_port_tty_get(&p->port); + if (!ttyp || !ttyp->termios) tmp.cflag = p->cflag; else - tmp.cflag = p->port.tty->termios->c_cflag; + tmp.cflag = ttyp->termios->c_cflag; + tty_kref_put(tty); copy: if (copy_to_user(argm, &tmp, sizeof(tmp))) { mutex_unlock(&moxa_openlock); @@ -880,8 +883,14 @@ static void moxa_board_deinit(struct moxa_board_conf *brd) /* pci hot-un-plug support */ for (a = 0; a < brd->numPorts; a++) - if (brd->ports[a].port.flags & ASYNC_INITIALIZED) - tty_hangup(brd->ports[a].port.tty); + if (brd->ports[a].port.flags & ASYNC_INITIALIZED) { + struct tty_struct *tty = tty_port_tty_get( + &brd->ports[a].port); + if (tty) { + tty_hangup(tty); + tty_kref_put(tty); + } + } while (1) { opened = 0; for (a = 0; a < brd->numPorts; a++) @@ -1096,13 +1105,14 @@ static void __exit moxa_exit(void) module_init(moxa_init); module_exit(moxa_exit); -static void moxa_close_port(struct moxa_port *ch) +static void moxa_close_port(struct tty_struct *tty) { - moxa_shut_down(ch); + struct moxa_port *ch = tty->driver_data; + moxa_shut_down(tty); MoxaPortFlushData(ch, 2); ch->port.flags &= ~ASYNC_NORMAL_ACTIVE; - ch->port.tty->driver_data = NULL; - ch->port.tty = NULL; + tty->driver_data = NULL; + tty_port_tty_set(&ch->port, NULL); } static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp, @@ -1161,7 +1171,7 @@ static int moxa_open(struct tty_struct *tty, struct file *filp) ch = &brd->ports[port % MAX_PORTS_PER_BOARD]; ch->port.count++; tty->driver_data = ch; - ch->port.tty = tty; + tty_port_tty_set(&ch->port, tty); if (!(ch->port.flags & ASYNC_INITIALIZED)) { ch->statusflags = 0; moxa_set_tty_param(tty, tty->termios); @@ -1179,7 +1189,7 @@ static int moxa_open(struct tty_struct *tty, struct file *filp) if (retval) { if (ch->port.count) /* 0 means already hung up... */ if (--ch->port.count == 0) - moxa_close_port(ch); + moxa_close_port(tty); } else ch->port.flags |= ASYNC_NORMAL_ACTIVE; mutex_unlock(&moxa_openlock); @@ -1219,7 +1229,7 @@ static void moxa_close(struct tty_struct *tty, struct file *filp) tty_wait_until_sent(tty, 30 * HZ); /* 30 seconds timeout */ } - moxa_close_port(ch); + moxa_close_port(tty); unlock: mutex_unlock(&moxa_openlock); } @@ -1234,7 +1244,7 @@ static int moxa_write(struct tty_struct *tty, return 0; spin_lock_bh(&moxa_lock); - len = MoxaPortWriteData(ch, buf, count); + len = MoxaPortWriteData(tty, buf, count); spin_unlock_bh(&moxa_lock); ch->statusflags |= LOWWAIT; @@ -1409,7 +1419,7 @@ static void moxa_hangup(struct tty_struct *tty) return; } ch->port.count = 0; - moxa_close_port(ch); + moxa_close_port(tty); mutex_unlock(&moxa_openlock); wake_up_interruptible(&ch->port.open_wait); @@ -1417,11 +1427,14 @@ static void moxa_hangup(struct tty_struct *tty) static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd) { + struct tty_struct *tty; dcd = !!dcd; - if (dcd != p->DCDState && p->port.tty && C_CLOCAL(p->port.tty)) { - if (!dcd) - tty_hangup(p->port.tty); + if (dcd != p->DCDState) { + tty = tty_port_tty_get(&p->port); + if (tty && C_CLOCAL(tty) && !dcd) + tty_hangup(tty); + tty_kref_put(tty); } p->DCDState = dcd; } @@ -1429,7 +1442,7 @@ static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd) static int moxa_poll_port(struct moxa_port *p, unsigned int handle, u16 __iomem *ip) { - struct tty_struct *tty = p->port.tty; + struct tty_struct *tty = tty_port_tty_get(&p->port); void __iomem *ofsAddr; unsigned int inited = p->port.flags & ASYNC_INITIALIZED; u16 intr; @@ -1476,6 +1489,7 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle, tty_insert_flip_char(tty, 0, TTY_BREAK); tty_schedule_flip(tty); } + tty_kref_put(tty); if (intr & IntrLine) moxa_new_dcdstate(p, readb(ofsAddr + FlagStat) & DCD_state); @@ -1560,9 +1574,9 @@ static void moxa_setup_empty_event(struct tty_struct *tty) spin_unlock_bh(&moxa_lock); } -static void moxa_shut_down(struct moxa_port *ch) +static void moxa_shut_down(struct tty_struct *tty) { - struct tty_struct *tp = ch->port.tty; + struct moxa_port *ch = tty->driver_data; if (!(ch->port.flags & ASYNC_INITIALIZED)) return; @@ -1572,7 +1586,7 @@ static void moxa_shut_down(struct moxa_port *ch) /* * If we're a modem control device and HUPCL is on, drop RTS & DTR. */ - if (C_HUPCL(tp)) + if (C_HUPCL(tty)) MoxaPortLineCtrl(ch, 0, 0); spin_lock_bh(&moxa_lock); @@ -1953,9 +1967,10 @@ static int MoxaPortLineStatus(struct moxa_port *port) return val; } -static int MoxaPortWriteData(struct moxa_port *port, +static int MoxaPortWriteData(struct tty_struct *tty, const unsigned char *buffer, int len) { + struct moxa_port *port = tty->driver_data; void __iomem *baseAddr, *ofsAddr, *ofs; unsigned int c, total; u16 head, tail, tx_mask, spage, epage; -- cgit v1.2.3-18-g5258