TTY: add tty_port_tty_hangup helper

It allows for cleaning up on a considerable amount of places. They did
port_get, hangup, kref_put. Now the only thing needed is to call
tty_port_tty_hangup which does exactly that. And they can also decide
whether to consider CLOCAL or completely ignore that.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/um/drivers/chan_kern.c

@@ -568,11 +568,7 @@ void chan_interrupt(struct line *line, int irq)
 		reactivate_fd(chan->fd, irq);
 	if (err == -EIO) {
 		if (chan->primary) {
-			struct tty_struct *tty = tty_port_tty_get(&line->port);
-			if (tty != NULL) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
+			tty_port_tty_hangup(&line->port, false);
 			if (line->chan_out != chan)
 				close_one_chan(line->chan_out, 1);
 		}

drivers/mmc/card/sdio_uart.c

@@ -134,7 +134,6 @@ static void sdio_uart_port_put(struct sdio_uart_port *port)
 static void sdio_uart_port_remove(struct sdio_uart_port *port)
 {
 	struct sdio_func *func;
-	struct tty_struct *tty;
 
 	BUG_ON(sdio_uart_table[port->index] != port);
 
@@ -155,12 +154,8 @@ static void sdio_uart_port_remove(struct sdio_uart_port *port)
 	sdio_claim_host(func);
 	port->func = NULL;
 	mutex_unlock(&port->func_lock);
-	tty = tty_port_tty_get(&port->port);
 	/* tty_hangup is async so is this safe as is ?? */
-	if (tty) {
-		tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	tty_port_tty_hangup(&port->port, false);
 	mutex_unlock(&port->port.mutex);
 	sdio_release_irq(func);
 	sdio_disable_func(func);
@@ -492,11 +487,7 @@ static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
 			wake_up_interruptible(&port->port.open_wait);
 		else {
 			/* DCD drop - hang up if tty attached */
-			tty = tty_port_tty_get(&port->port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
+			tty_port_tty_hangup(&port->port, false);
 		}
 	}
 	if (status & UART_MSR_DCTS) {

drivers/net/usb/hso.c

@@ -3124,18 +3124,13 @@ static void hso_serial_ref_free(struct kref *ref)
 static void hso_free_interface(struct usb_interface *interface)
 {
 	struct hso_serial *hso_dev;
-	struct tty_struct *tty;
 	int i;
 
 	for (i = 0; i < HSO_SERIAL_TTY_MINORS; i++) {
 		if (serial_table[i] &&
 		    (serial_table[i]->interface == interface)) {
 			hso_dev = dev2ser(serial_table[i]);
-			tty = tty_port_tty_get(&hso_dev->port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
+			tty_port_tty_hangup(&hso_dev->port, false);
 			mutex_lock(&hso_dev->parent->mutex);
 			hso_dev->parent->usb_gone = 1;
 			mutex_unlock(&hso_dev->parent->mutex);

drivers/tty/cyclades.c

@@ -1124,14 +1124,8 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
 					readl(&info->u.cyz.ch_ctrl->rs_status);
 				if (dcd & C_RS_DCD)
 					wake_up_interruptible(&info->port.open_wait);
-				else {
-					struct tty_struct *tty;
-					tty = tty_port_tty_get(&info->port);
-					if (tty) {
-						tty_hangup(tty);
-						tty_kref_put(tty);
-					}
-				}
+				else
+					tty_port_tty_hangup(&info->port, false);
 			}
 			break;
 		case C_CM_MCTS:

drivers/tty/moxa.c

@@ -913,16 +913,12 @@ 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) {
-			struct tty_struct *tty = tty_port_tty_get(
-						&brd->ports[a].port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
-		}
+		if (brd->ports[a].port.flags & ASYNC_INITIALIZED)
+			tty_port_tty_hangup(&brd->ports[a].port, false);
+
 	for (a = 0; a < MAX_PORTS_PER_BOARD; a++)
 		tty_port_destroy(&brd->ports[a].port);
+
 	while (1) {
 		opened = 0;
 		for (a = 0; a < brd->numPorts; a++)
@@ -1365,18 +1361,15 @@ static void moxa_hangup(struct tty_struct *tty)
 
 static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
 {
-	struct tty_struct *tty;
 	unsigned long flags;
 	dcd = !!dcd;
 
 	spin_lock_irqsave(&p->port.lock, flags);
 	if (dcd != p->DCDState) {
         	p->DCDState = dcd;
         	spin_unlock_irqrestore(&p->port.lock, flags);
-		tty = tty_port_tty_get(&p->port);
-		if (tty && !C_CLOCAL(tty) && !dcd)
-			tty_hangup(tty);
-		tty_kref_put(tty);
+		if (!dcd)
+			tty_port_tty_hangup(&p->port, true);
 	}
 	else
 		spin_unlock_irqrestore(&p->port.lock, flags);

drivers/tty/n_gsm.c

@@ -1418,11 +1418,7 @@ static void gsm_dlci_close(struct gsm_dlci *dlci)
 		pr_debug("DLCI %d goes closed.\n", dlci->addr);
 	dlci->state = DLCI_CLOSED;
 	if (dlci->addr != 0) {
-		struct tty_struct  *tty = tty_port_tty_get(&dlci->port);
-		if (tty) {
-			tty_hangup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_hangup(&dlci->port, false);
 		kfifo_reset(dlci->fifo);
 	} else
 		dlci->gsm->dead = 1;

drivers/tty/nozomi.c

@@ -1501,12 +1501,9 @@ static void tty_exit(struct nozomi *dc)
 
 	DBG1(" ");
 
-	for (i = 0; i < MAX_PORT; ++i) {
-		struct tty_struct *tty = tty_port_tty_get(&dc->port[i].port);
-		if (tty && list_empty(&tty->hangup_work.entry))
-			tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	for (i = 0; i < MAX_PORT; ++i)
+		tty_port_tty_hangup(&dc->port[i].port, false);
+
 	/* Racy below - surely should wait for scheduled work to be done or
 	   complete off a hangup method ? */
 	while (dc->open_ttys)

drivers/tty/rocket.c

@@ -521,15 +521,10 @@ static void rp_handle_port(struct r_port *info)
 		       (ChanStatus & CD_ACT) ? "on" : "off");
 #endif
 		if (!(ChanStatus & CD_ACT) && info->cd_status) {
-			struct tty_struct *tty;
 #ifdef ROCKET_DEBUG_HANGUP
 			printk(KERN_INFO "CD drop, calling hangup.\n");
 #endif
-			tty = tty_port_tty_get(&info->port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
+			tty_port_tty_hangup(&info->port, false);
 		}
 		info->cd_status = (ChanStatus & CD_ACT) ? 1 : 0;
 		wake_up_interruptible(&info->port.open_wait);

drivers/tty/serial/ifx6x60.c

@@ -269,23 +269,6 @@ static void mrdy_assert(struct ifx_spi_device *ifx_dev)
 	mrdy_set_high(ifx_dev);
 }
 
-/**
- *	ifx_spi_hangup		-	hang up an IFX device
- *	@ifx_dev: our SPI device
- *
- *	Hang up the tty attached to the IFX device if one is currently
- *	open. If not take no action
- */
-static void ifx_spi_ttyhangup(struct ifx_spi_device *ifx_dev)
-{
-	struct tty_port *pport = &ifx_dev->tty_port;
-	struct tty_struct *tty = tty_port_tty_get(pport);
-	if (tty) {
-		tty_hangup(tty);
-		tty_kref_put(tty);
-	}
-}
-
 /**
  *	ifx_spi_timeout		-	SPI timeout
  *	@arg: our SPI device
@@ -298,7 +281,7 @@ static void ifx_spi_timeout(unsigned long arg)
 	struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *)arg;
 
 	dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
-	ifx_spi_ttyhangup(ifx_dev);
+	tty_port_tty_hangup(&ifx_dev->tty_port, false);
 	mrdy_set_low(ifx_dev);
 	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 }
@@ -933,7 +916,7 @@ static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
 		set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
 		if (!solreset) {
 			/* unsolicited reset  */
-			ifx_spi_ttyhangup(ifx_dev);
+			tty_port_tty_hangup(&ifx_dev->tty_port, false);
 		}
 	} else {
 		/* exited reset */

drivers/tty/tty_port.c

@@ -232,6 +232,23 @@ void tty_port_hangup(struct tty_port *port)
 }
 EXPORT_SYMBOL(tty_port_hangup);
 
+/**
+ * tty_port_tty_hangup - helper to hang up a tty
+ *
+ * @port: tty port
+ * @check_clocal: hang only ttys with CLOCAL unset?
+ */
+void tty_port_tty_hangup(struct tty_port *port, bool check_clocal)
+{
+	struct tty_struct *tty = tty_port_tty_get(port);
+
+	if (tty && (!check_clocal || !C_CLOCAL(tty))) {
+		tty_hangup(tty);
+		tty_kref_put(tty);
+	}
+}
+EXPORT_SYMBOL_GPL(tty_port_tty_hangup);
+
 /**
  * tty_port_tty_wakeup - helper to wake up a tty
  *

drivers/usb/class/cdc-acm.c

@@ -292,7 +292,6 @@ static void acm_ctrl_irq(struct urb *urb)
 {
 	struct acm *acm = urb->context;
 	struct usb_cdc_notification *dr = urb->transfer_buffer;
-	struct tty_struct *tty;
 	unsigned char *data;
 	int newctrl;
 	int retval;
@@ -327,17 +326,12 @@ static void acm_ctrl_irq(struct urb *urb)
 		break;
 
 	case USB_CDC_NOTIFY_SERIAL_STATE:
-		tty = tty_port_tty_get(&acm->port);
 		newctrl = get_unaligned_le16(data);
 
-		if (tty) {
-			if (!acm->clocal &&
-				(acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
-				dev_dbg(&acm->control->dev,
-					"%s - calling hangup\n", __func__);
-				tty_hangup(tty);
-			}
-			tty_kref_put(tty);
+		if (!acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
+			dev_dbg(&acm->control->dev, "%s - calling hangup\n",
+					__func__);
+			tty_port_tty_hangup(&acm->port, false);
 		}
 
 		acm->ctrlin = newctrl;
@@ -1498,15 +1492,9 @@ static int acm_resume(struct usb_interface *intf)
 static int acm_reset_resume(struct usb_interface *intf)
 {
 	struct acm *acm = usb_get_intfdata(intf);
-	struct tty_struct *tty;
 
-	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
-		tty = tty_port_tty_get(&acm->port);
-		if (tty) {
-			tty_hangup(tty);
-			tty_kref_put(tty);
-		}
-	}
+	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags))
+		tty_port_tty_hangup(&acm->port, false);
 
 	return acm_resume(intf);
 }

drivers/usb/serial/keyspan.c

@@ -378,7 +378,6 @@ static void	usa26_instat_callback(struct urb *urb)
 	struct usb_serial			*serial;
 	struct usb_serial_port			*port;
 	struct keyspan_port_private	 	*p_priv;
-	struct tty_struct			*tty;
 	int old_dcd_state, err;
 	int status = urb->status;
 
@@ -421,12 +420,8 @@ static void	usa26_instat_callback(struct urb *urb)
 	p_priv->dcd_state = ((msg->gpia_dcd) ? 1 : 0);
 	p_priv->ri_state = ((msg->ri) ? 1 : 0);
 
-	if (old_dcd_state != p_priv->dcd_state) {
-		tty = tty_port_tty_get(&port->port);
-		if (tty && !C_CLOCAL(tty))
-			tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	if (old_dcd_state != p_priv->dcd_state)
+		tty_port_tty_hangup(&port->port, true);
 
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -510,7 +505,6 @@ static void	usa28_instat_callback(struct urb *urb)
 	struct usb_serial			*serial;
 	struct usb_serial_port			*port;
 	struct keyspan_port_private	 	*p_priv;
-	struct tty_struct			*tty;
 	int old_dcd_state;
 	int status = urb->status;
 
@@ -551,12 +545,8 @@ static void	usa28_instat_callback(struct urb *urb)
 	p_priv->dcd_state = ((msg->dcd) ? 1 : 0);
 	p_priv->ri_state = ((msg->ri) ? 1 : 0);
 
-	if (old_dcd_state != p_priv->dcd_state && old_dcd_state) {
-		tty = tty_port_tty_get(&port->port);
-		if (tty && !C_CLOCAL(tty))
-			tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
+		tty_port_tty_hangup(&port->port, true);
 
 		/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -642,12 +632,8 @@ static void	usa49_instat_callback(struct urb *urb)
 	p_priv->dcd_state = ((msg->dcd) ? 1 : 0);
 	p_priv->ri_state = ((msg->ri) ? 1 : 0);
 
-	if (old_dcd_state != p_priv->dcd_state && old_dcd_state) {
-		struct tty_struct *tty = tty_port_tty_get(&port->port);
-		if (tty && !C_CLOCAL(tty))
-			tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
+		tty_port_tty_hangup(&port->port, true);
 
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -851,7 +837,6 @@ static void	usa90_instat_callback(struct urb *urb)
 	struct usb_serial			*serial;
 	struct usb_serial_port			*port;
 	struct keyspan_port_private	 	*p_priv;
-	struct tty_struct			*tty;
 	int old_dcd_state, err;
 	int status = urb->status;
 
@@ -880,12 +865,8 @@ static void	usa90_instat_callback(struct urb *urb)
 	p_priv->dcd_state = ((msg->dcd) ? 1 : 0);
 	p_priv->ri_state = ((msg->ri) ? 1 : 0);
 
-	if (old_dcd_state != p_priv->dcd_state && old_dcd_state) {
-		tty = tty_port_tty_get(&port->port);
-		if (tty && !C_CLOCAL(tty))
-			tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
+		tty_port_tty_hangup(&port->port, true);
 
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -953,12 +934,8 @@ static void	usa67_instat_callback(struct urb *urb)
 	p_priv->cts_state = ((msg->hskia_cts) ? 1 : 0);
 	p_priv->dcd_state = ((msg->gpia_dcd) ? 1 : 0);
 
-	if (old_dcd_state != p_priv->dcd_state && old_dcd_state) {
-		struct tty_struct *tty = tty_port_tty_get(&port->port);
-		if (tty && !C_CLOCAL(tty))
-			tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
+		tty_port_tty_hangup(&port->port, true);
 
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);