7 files changed, 40 insertions, 38 deletions

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index e61c36cbb866..c193af6a628f 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -636,6 +636,7 @@ struct console xenboot_console = {
         .name           = "xenboot",
         .write          = xenboot_write_console,
         .flags          = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
+        .index          = -1,
 };
 #endif  /* CONFIG_EARLY_PRINTK */
 
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index c9a9ddd1d0bc..7a744b69c3d1 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1758,8 +1758,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
                 canon_change = (old->c_lflag ^ tty->termios.c_lflag) & ICANON;
         if (canon_change) {
                 bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
-                ldata->line_start = 0;
-                ldata->canon_head = ldata->read_tail;
+                ldata->line_start = ldata->canon_head = ldata->read_tail;
                 ldata->erasing = 0;
                 ldata->lnext = 0;
         }
@@ -2184,28 +2183,34 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
                 if (!input_available_p(tty, 0)) {
                         if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
-                                retval = -EIO;
-                                break;
-                        }
-                        if (tty_hung_up_p(file))
-                                break;
-                        if (!timeout)
-                                break;
-                        if (file->f_flags & O_NONBLOCK) {
-                                retval = -EAGAIN;
-                                break;
-                        }
-                        if (signal_pending(current)) {
-                                retval = -ERESTARTSYS;
-                                break;
-                        }
-                        n_tty_set_room(tty);
-                        up_read(&tty->termios_rwsem);
+                                up_read(&tty->termios_rwsem);
+                                tty_flush_to_ldisc(tty);
+                                down_read(&tty->termios_rwsem);
+                                if (!input_available_p(tty, 0)) {
+                                        retval = -EIO;
+                                        break;
+                                }
+                        } else {
+                                if (tty_hung_up_p(file))
+                                        break;
+                                if (!timeout)
+                                        break;
+                                if (file->f_flags & O_NONBLOCK) {
+                                        retval = -EAGAIN;
+                                        break;
+                                }
+                                if (signal_pending(current)) {
+                                        retval = -ERESTARTSYS;
+                                        break;
+                                }
+                                n_tty_set_room(tty);
+                                up_read(&tty->termios_rwsem);
 
-                        timeout = schedule_timeout(timeout);
+                                timeout = schedule_timeout(timeout);
 
-                        down_read(&tty->termios_rwsem);
-                        continue;
+                                down_read(&tty->termios_rwsem);
+                                continue;
+                        }
                 }
                 __set_current_state(TASK_RUNNING);
 
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index a0ebbc9ce5cd..042aa077b5b3 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1912,9 +1912,6 @@ static int serial_imx_probe_dt(struct imx_port *sport,
 
         sport->devdata = of_id->data;
 
-        if (of_device_is_stdout_path(np))
-                add_preferred_console(imx_reg.cons->name, sport->port.line, 0);
-
         return 0;
 }
 #else
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 52379e56a31e..44077c0b7670 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -667,30 +667,21 @@ static int pop_tx_x(struct eg20t_port *priv, unsigned char *buf)
 
 static int dma_push_rx(struct eg20t_port *priv, int size)
 {
-        struct tty_struct *tty;
         int room;
         struct uart_port *port = &priv->port;
         struct tty_port *tport = &port->state->port;
 
-        port = &priv->port;
-        tty = tty_port_tty_get(tport);
-        if (!tty) {
-                dev_dbg(priv->port.dev, "%s:tty is busy now", __func__);
-                return 0;
-        }
-
         room = tty_buffer_request_room(tport, size);
 
         if (room < size)
                 dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
                          size - room);
         if (!room)
-                return room;
+                return 0;
 
         tty_insert_flip_string(tport, sg_virt(&priv->sg_rx), size);
 
         port->icount.rx += room;
-        tty_kref_put(tty);
 
         return room;
 }
@@ -1098,6 +1089,8 @@ static void pch_uart_err_ir(struct eg20t_port *priv, unsigned int lsr)
         if (tty == NULL) {
                 for (i = 0; error_msg[i] != NULL; i++)
                         dev_err(&priv->pdev->dev, error_msg[i]);
+        } else {
+                tty_kref_put(tty);
         }
 }
 
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index d0d972f7e43e..0489a2bdcdf9 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -732,7 +732,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data)
 static void tegra_uart_stop_rx(struct uart_port *u)
 {
         struct tegra_uart_port *tup = to_tegra_uport(u);
-        struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
+        struct tty_struct *tty;
         struct tty_port *port = &u->state->port;
         struct dma_tx_state state;
         unsigned long ier;
@@ -744,6 +744,8 @@ static void tegra_uart_stop_rx(struct uart_port *u)
         if (!tup->rx_in_progress)
                 return;
 
+        tty = tty_port_tty_get(&tup->uport.state->port);
+
         tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */
 
         ier = tup->ier_shadow;
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index 93b697a0de65..15ad6fcda88b 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -561,12 +561,13 @@ static int vt8500_serial_probe(struct platform_device *pdev)
         if (!mmres || !irqres)
                 return -ENODEV;
 
-        if (np)
+        if (np) {
                 port = of_alias_get_id(np, "serial");
                 if (port >= VT8500_MAX_PORTS)
                         port = -1;
-        else
+        } else {
                 port = -1;
+        }
 
         if (port < 0) {
                 /* calculate the port id */
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 03ba081c5772..6fd60fece6b4 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -1201,6 +1201,9 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
                 }
                 return 0;
         case TCFLSH:
+                retval = tty_check_change(tty);
+                if (retval)
+                        return retval;
                 return __tty_perform_flush(tty, arg);
         default:
                 /* Try the mode commands */