X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Ftty%2Fn_tty.c;h=4671f8d671bee65bee26e7d16b8abe3f7f6e5424;hb=2d7a0bb8c3a8ab75ea5af4a280d1aa33f852c18c;hp=39d6ab6551e0884db2237f6ffeba184de92f4c22;hpb=0b576372e86c8e6bee01506651b21ec0fe8a1698;p=pandora-kernel.git

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 39d6ab6551e0..4671f8d671be 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1298,8 +1298,7 @@ handle_newline:
 			tty->canon_data++;
 			spin_unlock_irqrestore(&tty->read_lock, flags);
 			kill_fasync(&tty->fasync, SIGIO, POLL_IN);
-			if (waitqueue_active(&tty->read_wait))
-				wake_up_interruptible(&tty->read_wait);
+			wake_up_interruptible(&tty->read_wait);
 			return;
 		}
 	}
@@ -1422,8 +1421,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
 		L_EXTPROC(tty)) {
 		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
-		if (waitqueue_active(&tty->read_wait))
-			wake_up_interruptible(&tty->read_wait);
+		wake_up_interruptible(&tty->read_wait);
 	}
 
 	/*
@@ -1530,6 +1528,14 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 			tty->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);
@@ -1728,7 +1734,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
 do_it_again:
 
-	BUG_ON(!tty->read_buf);
+	if (WARN_ON(!tty->read_buf))
+		return -EAGAIN;
 
 	c = job_control(tty, file);
 	if (c < 0)
@@ -1988,7 +1995,9 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 				tty->ops->flush_chars(tty);
 		} else {
 			while (nr > 0) {
+				mutex_lock(&tty->output_lock);
 				c = tty->ops->write(tty, b, nr);
+				mutex_unlock(&tty->output_lock);
 				if (c < 0) {
 					retval = c;
 					goto break_out;