1 files changed, 24 insertions, 4 deletions

diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 7e0884ecc74f..94c1ec2dd754 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -140,6 +140,8 @@ struct n_hdlc {
 	struct n_hdlc_buf_list	rx_buf_list;
 	struct n_hdlc_buf_list	tx_free_buf_list;
 	struct n_hdlc_buf_list	rx_free_buf_list;
+	struct work_struct	write_work;
+	struct tty_struct	*tty_for_write_work;
 };
 
 /*
@@ -154,6 +156,7 @@ static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
 /* Local functions */
 
 static struct n_hdlc *n_hdlc_alloc(void);
+static void n_hdlc_tty_write_work(struct work_struct *work);
 
 /* max frame size for memory allocations */
 static int maxframe = 4096;
@@ -210,6 +213,8 @@ static void n_hdlc_tty_close(struct tty_struct *tty)
 	wake_up_interruptible(&tty->read_wait);
 	wake_up_interruptible(&tty->write_wait);
 
+	cancel_work_sync(&n_hdlc->write_work);
+
 	n_hdlc_free_buf_list(&n_hdlc->rx_free_buf_list);
 	n_hdlc_free_buf_list(&n_hdlc->tx_free_buf_list);
 	n_hdlc_free_buf_list(&n_hdlc->rx_buf_list);
@@ -241,6 +246,8 @@ static int n_hdlc_tty_open(struct tty_struct *tty)
 		return -ENFILE;
 	}
 
+	INIT_WORK(&n_hdlc->write_work, n_hdlc_tty_write_work);
+	n_hdlc->tty_for_write_work = tty;
 	tty->disc_data = n_hdlc;
 	tty->receive_room = 65536;
 
@@ -335,6 +342,20 @@ check_again:
 }	/* end of n_hdlc_send_frames() */
 
 /**
+ * n_hdlc_tty_write_work - Asynchronous callback for transmit wakeup
+ * @work: pointer to work_struct
+ *
+ * Called when low level device driver can accept more send data.
+ */
+static void n_hdlc_tty_write_work(struct work_struct *work)
+{
+	struct n_hdlc *n_hdlc = container_of(work, struct n_hdlc, write_work);
+	struct tty_struct *tty = n_hdlc->tty_for_write_work;
+
+	n_hdlc_send_frames(n_hdlc, tty);
+}	/* end of n_hdlc_tty_write_work() */
+
+/**
  * n_hdlc_tty_wakeup - Callback for transmit wakeup
  * @tty: pointer to associated tty instance data
  *
@@ -344,7 +365,7 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
 {
 	struct n_hdlc *n_hdlc = tty->disc_data;
 
-	n_hdlc_send_frames(n_hdlc, tty);
+	schedule_work(&n_hdlc->write_work);
 }	/* end of n_hdlc_tty_wakeup() */
 
 /**
@@ -572,14 +593,13 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
 /**
  * n_hdlc_tty_ioctl - process IOCTL system call for the tty device.
  * @tty: pointer to tty instance data
- * @file: pointer to open file object for device
  * @cmd: IOCTL command code
  * @arg: argument for IOCTL call (cmd dependent)
  *
  * Returns command dependent result.
  */
-static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
-			    unsigned int cmd, unsigned long arg)
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
+			    unsigned long arg)
 {
 	struct n_hdlc *n_hdlc = tty->disc_data;
 	int error = 0;