Merge remote-tracking branch 'lsk/v3.10/topic/coresight' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / drivers / tty / n_tty.c

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index d655416087b7099d7639923c7c0a478c72a5afbe..6cfe4019abc63b3f3321df606e57bdd38ed6be72 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1573,6 +1573,14 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
                        ldata->real_raw = 0;
        }
        n_tty_set_room(tty);
+       /*
+        * Fix tty hang when I_IXON(tty) is cleared, but the tty
+        * been stopped by STOP_CHAR(tty) before it.
+        */
+       if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) {
+               start_tty(tty);
+       }
+
        /* The termios change make the tty ready for I/O */
        wake_up_interruptible(&tty->write_wait);
        wake_up_interruptible(&tty->read_wait);
@@ -2058,8 +2066,12 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
                        if (tty->ops->flush_chars)
                                tty->ops->flush_chars(tty);
                } else {
+                       struct n_tty_data *ldata = tty->disc_data;
+
                        while (nr > 0) {
+                               mutex_lock(&ldata->output_lock);
                                c = tty->ops->write(tty, b, nr);
+                               mutex_unlock(&ldata->output_lock);
                                if (c < 0) {
                                        retval = c;
                                        goto break_out;