TTY: add tty_port_tty_wakeup helper

It allows for cleaning up on a considerable amount of places. They did
port_get, wakeup, kref_put. Now the only thing needed is to call
tty_port_tty_wakeup which does exactly that.

One exception is ifx6x60 where tty_wakeup was open-coded. We now call
tty_wakeup properly there.

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

arch/um/drivers/line.c

@@ -248,7 +248,6 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
 {
 	struct chan *chan = data;
 	struct line *line = chan->line;
-	struct tty_struct *tty;
 	int err;
 
 	/*
@@ -267,12 +266,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
 	}
 	spin_unlock(&line->lock);
 
-	tty = tty_port_tty_get(&line->port);
-	if (tty == NULL)
-		return IRQ_NONE;
-
-	tty_wakeup(tty);
-	tty_kref_put(tty);
+	tty_port_tty_wakeup(&line->port);
 
 	return IRQ_HANDLED;
 }

drivers/isdn/capi/capi.c

@@ -569,7 +569,6 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
 {
 	struct capidev *cdev = ap->private;
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-	struct tty_struct *tty;
 	struct capiminor *mp;
 	u16 datahandle;
 	struct capincci *np;
@@ -627,11 +626,7 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
 			 CAPIMSG_U16(skb->data, CAPIMSG_BASELEN + 4 + 2));
 		kfree_skb(skb);
 		capiminor_del_ack(mp, datahandle);
-		tty = tty_port_tty_get(&mp->port);
-		if (tty) {
-			tty_wakeup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_wakeup(&mp->port);
 		handle_minor_send(mp);
 
 	} else {

drivers/isdn/gigaset/interface.c

@@ -487,12 +487,8 @@ static const struct tty_operations if_ops = {
 static void if_wake(unsigned long data)
 {
 	struct cardstate *cs = (struct cardstate *)data;
-	struct tty_struct *tty = tty_port_tty_get(&cs->port);
 
-	if (tty) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
+	tty_port_tty_wakeup(&cs->port);
 }
 
 /*** interface to common ***/

drivers/net/usb/hso.c

@@ -1925,7 +1925,6 @@ static void hso_std_serial_write_bulk_callback(struct urb *urb)
 {
 	struct hso_serial *serial = urb->context;
 	int status = urb->status;
-	struct tty_struct *tty;
 
 	/* sanity check */
 	if (!serial) {
@@ -1941,11 +1940,7 @@ static void hso_std_serial_write_bulk_callback(struct urb *urb)
 		return;
 	}
 	hso_put_activity(serial->parent);
-	tty = tty_port_tty_get(&serial->port);
-	if (tty) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
+	tty_port_tty_wakeup(&serial->port);
 	hso_kick_transmit(serial);
 
 	D1(" ");
@@ -2008,12 +2003,8 @@ static void ctrl_callback(struct urb *urb)
 		put_rxbuf_data_and_resubmit_ctrl_urb(serial);
 		spin_unlock(&serial->serial_lock);
 	} else {
-		struct tty_struct *tty = tty_port_tty_get(&serial->port);
 		hso_put_activity(serial->parent);
-		if (tty) {
-			tty_wakeup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_wakeup(&serial->port);
 		/* response to a write command */
 		hso_kick_transmit(serial);
 	}

drivers/s390/char/sclp_tty.c

@@ -107,7 +107,6 @@ sclp_tty_write_room (struct tty_struct *tty)
 static void
 sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 {
-	struct tty_struct *tty;
 	unsigned long flags;
 	void *page;
 
@@ -125,12 +124,8 @@ sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 					    struct sclp_buffer, list);
 		spin_unlock_irqrestore(&sclp_tty_lock, flags);
 	} while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
-	/* check if the tty needs a wake up call */
-	tty = tty_port_tty_get(&sclp_port);
-	if (tty != NULL) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
+
+	tty_port_tty_wakeup(&sclp_port);
 }
 
 static inline void

drivers/s390/char/sclp_vt220.c

@@ -114,7 +114,6 @@ static struct sclp_register sclp_vt220_register = {
 static void
 sclp_vt220_process_queue(struct sclp_vt220_request *request)
 {
-	struct tty_struct *tty;
 	unsigned long flags;
 	void *page;
 
@@ -139,12 +138,7 @@ sclp_vt220_process_queue(struct sclp_vt220_request *request)
 	} while (__sclp_vt220_emit(request));
 	if (request == NULL && sclp_vt220_flush_later)
 		sclp_vt220_emit_current();
-	/* Check if the tty needs a wake up call */
-	tty = tty_port_tty_get(&sclp_vt220_port);
-	if (tty) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
+	tty_port_tty_wakeup(&sclp_vt220_port);
 }
 
 #define SCLP_BUFFER_MAX_RETRY		1

drivers/staging/fwserial/fwserial.c

@@ -744,7 +744,6 @@ static void fwtty_tx_complete(struct fw_card *card, int rcode,
 			      struct fwtty_transaction *txn)
 {
 	struct fwtty_port *port = txn->port;
-	struct tty_struct *tty;
 	int len;
 
 	fwtty_dbg(port, "rcode: %d", rcode);
@@ -769,13 +768,8 @@ static void fwtty_tx_complete(struct fw_card *card, int rcode,
 		port->stats.dropped += txn->dma_pended.len;
 	}
 
-	if (len < WAKEUP_CHARS) {
-		tty = tty_port_tty_get(&port->port);
-		if (tty) {
-			tty_wakeup(tty);
-			tty_kref_put(tty);
-		}
-	}
+	if (len < WAKEUP_CHARS)
+		tty_port_tty_wakeup(&port->port);
 }
 
 static int fwtty_tx(struct fwtty_port *port, bool drain)

drivers/staging/serqt_usb2/serqt_usb2.c

@@ -264,7 +264,6 @@ static void ProcessRxChar(struct usb_serial_port *port, unsigned char data)
 
 static void qt_write_bulk_callback(struct urb *urb)
 {
-	struct tty_struct *tty;
 	int status;
 	struct quatech_port *quatech_port;
 
@@ -278,11 +277,7 @@ static void qt_write_bulk_callback(struct urb *urb)
 
 	quatech_port = urb->context;
 
-	tty = tty_port_tty_get(&quatech_port->port->port);
-
-	if (tty)
-		tty_wakeup(tty);
-	tty_kref_put(tty);
+	tty_port_tty_wakeup(&quatech_port->port->port);
 }
 
 static void qt_interrupt_callback(struct urb *urb)

drivers/tty/ehv_bytechan.c

@@ -472,13 +472,9 @@ static void ehv_bc_tx_dequeue(struct ehv_bc_data *bc)
 static irqreturn_t ehv_bc_tty_tx_isr(int irq, void *data)
 {
 	struct ehv_bc_data *bc = data;
-	struct tty_struct *ttys = tty_port_tty_get(&bc->port);
 
 	ehv_bc_tx_dequeue(bc);
-	if (ttys) {
-		tty_wakeup(ttys);
-		tty_kref_put(ttys);
-	}
+	tty_port_tty_wakeup(&bc->port);
 
 	return IRQ_HANDLED;
 }

drivers/tty/hvc/hvsi.c

@@ -861,7 +861,6 @@ static void hvsi_write_worker(struct work_struct *work)
 {
 	struct hvsi_struct *hp =
 		container_of(work, struct hvsi_struct, writer.work);
-	struct tty_struct *tty;
 	unsigned long flags;
 #ifdef DEBUG
 	static long start_j = 0;
@@ -895,11 +894,7 @@ static void hvsi_write_worker(struct work_struct *work)
 		start_j = 0;
 #endif /* DEBUG */
 		wake_up_all(&hp->emptyq);
-		tty = tty_port_tty_get(&hp->port);
-		if (tty) {
-			tty_wakeup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_wakeup(&hp->port);
 	}
 
 out:

drivers/tty/nozomi.c

@@ -791,15 +791,13 @@ static int send_data(enum port_type index, struct nozomi *dc)
 	const u8 toggle = port->toggle_ul;
 	void __iomem *addr = port->ul_addr[toggle];
 	const u32 ul_size = port->ul_size[toggle];
-	struct tty_struct *tty = tty_port_tty_get(&port->port);
 
 	/* Get data from tty and place in buf for now */
 	size = kfifo_out(&port->fifo_ul, dc->send_buf,
 			   ul_size < SEND_BUF_MAX ? ul_size : SEND_BUF_MAX);
 
 	if (size == 0) {
 		DBG4("No more data to send, disable link:");
-		tty_kref_put(tty);
 		return 0;
 	}
 
@@ -809,10 +807,8 @@ static int send_data(enum port_type index, struct nozomi *dc)
 	write_mem32(addr, (u32 *) &size, 4);
 	write_mem32(addr + 4, (u32 *) dc->send_buf, size);
 
-	if (tty)
-		tty_wakeup(tty);
+	tty_port_tty_wakeup(&port->port);
 
-	tty_kref_put(tty);
 	return 1;
 }
 

drivers/tty/serial/ifx6x60.c

@@ -442,25 +442,6 @@ static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
 	txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
 }
 
-/**
- *	ifx_spi_wakeup_serial	-	SPI space made
- *	@port_data: our SPI device
- *
- *	We have emptied the FIFO enough that we want to get more data
- *	queued into it. Poke the line discipline via tty_wakeup so that
- *	it will feed us more bits
- */
-static void ifx_spi_wakeup_serial(struct ifx_spi_device *ifx_dev)
-{
-	struct tty_struct *tty;
-
-	tty = tty_port_tty_get(&ifx_dev->tty_port);
-	if (!tty)
-		return;
-	tty_wakeup(tty);
-	tty_kref_put(tty);
-}
-
 /**
  *	ifx_spi_prepare_tx_buffer	-	prepare transmit frame
  *	@ifx_dev: our SPI device
@@ -506,7 +487,7 @@ static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
 			tx_count += temp_count;
 			if (temp_count == queue_length)
 				/* poke port to get more data */
-				ifx_spi_wakeup_serial(ifx_dev);
+				tty_port_tty_wakeup(&ifx_dev->tty_port);
 			else /* more data in port, use next SPI message */
 				ifx_dev->spi_more = 1;
 		}
@@ -683,8 +664,6 @@ static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
 static void ifx_spi_complete(void *ctx)
 {
 	struct ifx_spi_device *ifx_dev = ctx;
-	struct tty_struct *tty;
-	struct tty_ldisc *ldisc = NULL;
 	int length;
 	int actual_length;
 	unsigned char more;
@@ -762,15 +741,7 @@ static void ifx_spi_complete(void *ctx)
 			 */
 			ifx_spi_power_state_clear(ifx_dev,
 						  IFX_SPI_POWER_DATA_PENDING);
-			tty = tty_port_tty_get(&ifx_dev->tty_port);
-			if (tty) {
-				ldisc = tty_ldisc_ref(tty);
-				if (ldisc) {
-					ldisc->ops->write_wakeup(tty);
-					tty_ldisc_deref(ldisc);
-				}
-				tty_kref_put(tty);
-			}
+			tty_port_tty_wakeup(&ifx_dev->tty_port);
 		}
 	}
 }

drivers/tty/tty_port.c

@@ -232,6 +232,22 @@ void tty_port_hangup(struct tty_port *port)
 }
 EXPORT_SYMBOL(tty_port_hangup);
 
+/**
+ * tty_port_tty_wakeup - helper to wake up a tty
+ *
+ * @port: tty port
+ */
+void tty_port_tty_wakeup(struct tty_port *port)
+{
+	struct tty_struct *tty = tty_port_tty_get(port);
+
+	if (tty) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
+	}
+}
+EXPORT_SYMBOL_GPL(tty_port_tty_wakeup);
+
 /**
  *	tty_port_carrier_raised	-	carrier raised check
  *	@port: tty port

drivers/usb/class/cdc-acm.c

@@ -475,15 +475,10 @@ static void acm_write_bulk(struct urb *urb)
 static void acm_softint(struct work_struct *work)
 {
 	struct acm *acm = container_of(work, struct acm, work);
-	struct tty_struct *tty;
 
 	dev_vdbg(&acm->data->dev, "%s\n", __func__);
 
-	tty = tty_port_tty_get(&acm->port);
-	if (!tty)
-		return;
-	tty_wakeup(tty);
-	tty_kref_put(tty);
+	tty_port_tty_wakeup(&acm->port);
 }
 
 /*

drivers/usb/serial/digi_acceleport.c

@@ -210,7 +210,6 @@ struct digi_port {
 
 /* Local Function Declarations */
 
-static void digi_wakeup_write(struct usb_serial_port *port);
 static void digi_wakeup_write_lock(struct work_struct *work);
 static int digi_write_oob_command(struct usb_serial_port *port,
 	unsigned char *buf, int count, int interruptible);
@@ -374,20 +373,10 @@ static void digi_wakeup_write_lock(struct work_struct *work)
 	unsigned long flags;
 
 	spin_lock_irqsave(&priv->dp_port_lock, flags);
-	digi_wakeup_write(port);
+	tty_port_tty_wakeup(&port->port);
 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
 }
 
-static void digi_wakeup_write(struct usb_serial_port *port)
-{
-	struct tty_struct *tty = tty_port_tty_get(&port->port);
-	if (tty) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
-}
-
-
 /*
  *  Digi Write OOB Command
  *
@@ -1044,7 +1033,7 @@ static void digi_write_bulk_callback(struct urb *urb)
 		}
 	}
 	/* wake up processes sleeping on writes immediately */
-	digi_wakeup_write(port);
+	tty_port_tty_wakeup(&port->port);
 	/* also queue up a wakeup at scheduler time, in case we */
 	/* lost the race in write_chan(). */
 	schedule_work(&priv->dp_wakeup_work);
@@ -1522,7 +1511,7 @@ static int digi_read_oob_callback(struct urb *urb)
 				/* port must be open to use tty struct */
 				if (rts) {
 					tty->hw_stopped = 0;
-					digi_wakeup_write(port);
+					tty_port_tty_wakeup(&port->port);
 				}
 			} else {
 				priv->dp_modem_signals &= ~TIOCM_CTS;