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>

16 files changed, 58 insertions, 148 deletions

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 15c553c239a1..bf42825ba54f 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/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);
                 }
diff --git a/drivers/mmc/card/sdio_uart.c b/drivers/mmc/card/sdio_uart.c
index c931dfe6a59c..f093cea0d060 100644
--- a/drivers/mmc/card/sdio_uart.c
+++ b/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) {
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index a7714b4f29ad..cba1d46e672e 100644
--- a/drivers/net/usb/hso.c
+++ b/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);
diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index 345bd0e0884e..33f83fee9fae 100644
--- a/drivers/tty/cyclades.c
+++ b/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:
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
index adeac255e526..1deaca4674e4 100644
--- a/drivers/tty/moxa.c
+++ b/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++)
@@ -1365,7 +1361,6 @@ 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;
 
@@ -1373,10 +1368,8 @@ static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
         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);
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 4a43ef5d7962..74d9a0258d7c 100644
--- a/drivers/tty/n_gsm.c
+++ b/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;
diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index 2e5bbdc09e1c..d6080c3831ef 100644
--- a/drivers/tty/nozomi.c
+++ b/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)
diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
index 1d270034bfc3..bbffd7a431e9 100644
--- a/drivers/tty/rocket.c
+++ b/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);
diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index d723d4193b90..2c77fed31a72 100644
--- a/drivers/tty/serial/ifx6x60.c
+++ b/drivers/tty/serial/ifx6x60.c
@@ -270,23 +270,6 @@ static void mrdy_assert(struct ifx_spi_device *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 */
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 8bb757c62ee2..7f38eeaafac3 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -233,6 +233,23 @@ 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
  *
  * @port: tty port
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 755766e4b756..27a18743275e 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/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 @@ err_out:
 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);
 }
diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
index 1fd1935c8316..b011478d2e5f 100644
--- a/drivers/usb/serial/keyspan.c
+++ b/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);
diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index f7d339d8187b..602d1f389a3b 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -1532,13 +1532,8 @@ static void option_instat_callback(struct urb *urb)
                         portdata->dsr_state = ((signals & 0x02) ? 1 : 0);
                         portdata->ri_state = ((signals & 0x08) ? 1 : 0);
 
-                        if (old_dcd_state && !portdata->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 && !portdata->dcd_state)
+                                tty_port_tty_hangup(&port->port, true);
                 } else {
                         dev_dbg(dev, "%s: type %x req %x\n", __func__,
                                 req_pkt->bRequestType, req_pkt->bRequest);
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index c13f6e747748..d66148a17fe3 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -628,7 +628,6 @@ static void sierra_instat_callback(struct urb *urb)
                         unsigned char signals = *((unsigned char *)
                                         urb->transfer_buffer +
                                         sizeof(struct usb_ctrlrequest));
-                        struct tty_struct *tty;
 
                         dev_dbg(&port->dev, "%s: signal x%x\n", __func__,
                                 signals);
@@ -639,11 +638,8 @@ static void sierra_instat_callback(struct urb *urb)
                         portdata->dsr_state = ((signals & 0x02) ? 1 : 0);
                         portdata->ri_state = ((signals & 0x08) ? 1 : 0);
 
-                        tty = tty_port_tty_get(&port->port);
-                        if (tty && !C_CLOCAL(tty) &&
-                                        old_dcd_state && !portdata->dcd_state)
-                                tty_hangup(tty);
-                        tty_kref_put(tty);
+                        if (old_dcd_state && !portdata->dcd_state)
+                                tty_port_tty_hangup(&port->port, true);
                 } else {
                         dev_dbg(&port->dev, "%s: type %x req %x\n",
                                 __func__, req_pkt->bRequestType,
diff --git a/include/linux/tty.h b/include/linux/tty.h
index b6e890a87eb1..d3548f871968 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -534,6 +534,7 @@ extern int tty_port_carrier_raised(struct tty_port *port);
 extern void tty_port_raise_dtr_rts(struct tty_port *port);
 extern void tty_port_lower_dtr_rts(struct tty_port *port);
 extern void tty_port_hangup(struct tty_port *port);
+extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
 extern void tty_port_tty_wakeup(struct tty_port *port);
 extern int tty_port_block_til_ready(struct tty_port *port,
                                 struct tty_struct *tty, struct file *filp);
diff --git a/net/irda/ircomm/ircomm_tty_attach.c b/net/irda/ircomm/ircomm_tty_attach.c
index edab393e0c82..a2a508f5f268 100644
--- a/net/irda/ircomm/ircomm_tty_attach.c
+++ b/net/irda/ircomm/ircomm_tty_attach.c
@@ -997,12 +997,8 @@ static int ircomm_tty_state_ready(struct ircomm_tty_cb *self,
                         self->settings.dce = IRCOMM_DELTA_CD;
                         ircomm_tty_check_modem_status(self);
                 } else {
-                        struct tty_struct *tty = tty_port_tty_get(&self->port);
                         IRDA_DEBUG(0, "%s(), hanging up!\n", __func__ );
-                        if (tty) {
-                                tty_hangup(tty);
-                                tty_kref_put(tty);
-                        }
+                        tty_port_tty_hangup(&self->port, false);
                 }
                 break;
         default: