Merge tag 'tty-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are some serial at tty driver fixes for 3.12-rc3

  The serial driver fixes some kref leaks, documentation is moved to the
  proper places, and the tty and n_tty fixes resolve some reported
  regressions.  There is still one outstanding tty regression fix that
  isn't in here yet, as I want to test it out some more, it will be sent
  for 3.12-rc4 if it checks out"

* tag 'tty-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: ar933x_uart: move devicetree binding documentation
  tty: Fix SIGTTOU not sent with tcflush()
  n_tty: Fix EOF push index when termios changes
  serial: pch_uart: remove unnecessary tty_port_tty_get
  serial: pch_uart: fix tty-kref leak in dma-rx path
  serial: pch_uart: fix tty-kref leak in rx-error path
  serial: tegra: fix tty-kref leak

5 files changed, 10 insertions, 13 deletions

diff --git a/Documentation/devicetree/bindings/tty/serial/qca,ar9330-uart.txt b/Documentation/devicetree/bindings/serial/qca,ar9330-uart.txt
index c5e032c85bf9..c5e032c85bf9 100644
--- a/Documentation/devicetree/bindings/tty/serial/qca,ar9330-uart.txt
+++ b/Documentation/devicetree/bindings/serial/qca,ar9330-uart.txt
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index c9a9ddd1d0bc..01bf5eb4f238 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;
         }
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/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 */