--- zzzz-none-000/linux-3.10.107/drivers/ipack/devices/ipoctal.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/ipack/devices/ipoctal.c	2021-02-04 17:41:59.000000000 +0000
@@ -55,6 +55,22 @@
 	u8 __iomem			*int_space;
 };
 
+static inline struct ipoctal *chan_to_ipoctal(struct ipoctal_channel *chan,
+					      unsigned int index)
+{
+	return container_of(chan, struct ipoctal, channel[index]);
+}
+
+static void ipoctal_reset_channel(struct ipoctal_channel *channel)
+{
+	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
+	channel->rx_enable = 0;
+	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
+	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
+	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
+	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
+}
+
 static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
 {
 	struct ipoctal_channel *channel;
@@ -72,12 +88,20 @@
 
 static int ipoctal_open(struct tty_struct *tty, struct file *file)
 {
-	struct ipoctal_channel *channel;
+	struct ipoctal_channel *channel = dev_get_drvdata(tty->dev);
+	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
+	int err;
 
-	channel = dev_get_drvdata(tty->dev);
 	tty->driver_data = channel;
 
-	return tty_port_open(&channel->tty_port, tty, file);
+	if (!ipack_get_carrier(ipoctal->dev))
+		return -EBUSY;
+
+	err = tty_port_open(&channel->tty_port, tty, file);
+	if (err)
+		ipack_put_carrier(ipoctal->dev);
+
+	return err;
 }
 
 static void ipoctal_reset_stats(struct ipoctal_stats *stats)
@@ -151,7 +175,6 @@
 				flag = TTY_FRAME;
 			}
 			if (sr & SR_RECEIVED_BREAK) {
-				iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
 				channel->stats.rcv_break++;
 				flag = TTY_BREAK;
 			}
@@ -177,24 +200,28 @@
 	if (channel->nb_bytes == 0)
 		return;
 
+	spin_lock(&channel->lock);
 	value = channel->tty_port.xmit_buf[*pointer_write];
 	iowrite8(value, &channel->regs->w.thr);
 	channel->stats.tx++;
 	(*pointer_write)++;
 	*pointer_write = *pointer_write % PAGE_SIZE;
 	channel->nb_bytes--;
+	spin_unlock(&channel->lock);
 }
 
 static void ipoctal_irq_channel(struct ipoctal_channel *channel)
 {
 	u8 isr, sr;
 
-	spin_lock(&channel->lock);
 	/* The HW is organized in pair of channels.  See which register we need
 	 * to read from */
 	isr = ioread8(&channel->block_regs->r.isr);
 	sr = ioread8(&channel->regs->r.sr);
 
+	if (isr & (IMR_DELTA_BREAK_A | IMR_DELTA_BREAK_B))
+		iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
+
 	if ((sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
 		iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
 		/* In case of RS-485, change from TX to RX when finishing TX.
@@ -213,8 +240,6 @@
 	/* TX of each character */
 	if ((isr & channel->isr_tx_rdy_mask) && (sr & SR_TX_READY))
 		ipoctal_irq_tx(channel);
-
-	spin_unlock(&channel->lock);
 }
 
 static irqreturn_t ipoctal_irq_handler(void *arg)
@@ -305,10 +330,7 @@
 			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_A;
 		}
 
-		iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
-		channel->rx_enable = 0;
-		iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
-		iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
+		ipoctal_reset_channel(channel);
 		iowrite8(MR1_CHRL_8_BITS | MR1_ERROR_CHAR | MR1_RxINT_RxRDY,
 			 &channel->regs->w.mr); /* mr1 */
 		iowrite8(0, &channel->regs->w.mr); /* mr2 */
@@ -324,13 +346,6 @@
 			 &block_regs[i].w.imr);
 	}
 
-	/*
-	 * IP-OCTAL has different addresses to copy its IRQ vector.
-	 * Depending of the carrier these addresses are accesible or not.
-	 * More info in the datasheet.
-	 */
-	ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
-				       ipoctal_irq_handler, ipoctal);
 	/* Dummy write */
 	iowrite8(1, ipoctal->mem8_space + 1);
 
@@ -391,6 +406,14 @@
 		dev_set_drvdata(tty_dev, channel);
 	}
 
+	/*
+	 * IP-OCTAL has different addresses to copy its IRQ vector.
+	 * Depending of the carrier these addresses are accesible or not.
+	 * More info in the datasheet.
+	 */
+	ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
+				       ipoctal_irq_handler, ipoctal);
+
 	return 0;
 }
 
@@ -467,11 +490,7 @@
 	cflag = tty->termios.c_cflag;
 
 	/* Disable and reset everything before change the setup */
-	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
+	ipoctal_reset_channel(channel);
 
 	/* Set Bits per chars */
 	switch (cflag & CSIZE) {
@@ -609,12 +628,7 @@
 
 	tty_port_hangup(&channel->tty_port);
 
-	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
-	channel->rx_enable = 0;
-	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
+	ipoctal_reset_channel(channel);
 
 	clear_bit(ASYNCB_INITIALIZED, &channel->tty_port.flags);
 	wake_up_interruptible(&channel->tty_port.open_wait);
@@ -627,15 +641,19 @@
 	if (channel == NULL)
 		return;
 
-	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
-	channel->rx_enable = 0;
-	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
-	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
+	ipoctal_reset_channel(channel);
 	clear_bit(ASYNCB_INITIALIZED, &channel->tty_port.flags);
 }
 
+static void ipoctal_cleanup(struct tty_struct *tty)
+{
+	struct ipoctal_channel *channel = tty->driver_data;
+	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
+
+	/* release the carrier driver */
+	ipack_put_carrier(ipoctal->dev);
+}
+
 static const struct tty_operations ipoctal_fops = {
 	.ioctl =		NULL,
 	.open =			ipoctal_open,
@@ -647,6 +665,7 @@
 	.get_icount =		ipoctal_get_icount,
 	.hangup =		ipoctal_hangup,
 	.shutdown =		ipoctal_shutdown,
+	.cleanup =              ipoctal_cleanup,
 };
 
 static int ipoctal_probe(struct ipack_device *dev)