1 files changed, 23 insertions, 14 deletions

diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index 82bcfb9c839a..a35bfd7ee80e 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -342,12 +342,10 @@ static int n_hdlc_tty_open (struct tty_struct *tty)
 #endif
         
         /* Flush any pending characters in the driver and discipline. */
-        
         if (tty->ldisc.flush_buffer)
-                tty->ldisc.flush_buffer (tty);
+                tty->ldisc.flush_buffer(tty);
 
-        if (tty->driver->flush_buffer)
-                tty->driver->flush_buffer (tty);
+        tty_driver_flush_buffer(tty);
                 
         if (debuglevel >= DEBUG_LEVEL_INFO)     
                 printk("%s(%d)n_hdlc_tty_open() success\n",__FILE__,__LINE__);
@@ -399,7 +397,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
                         
                 /* Send the next block of data to device */
                 tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
-                actual = tty->driver->write(tty, tbuf->buf, tbuf->count);
+                actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
 
                 /* rollback was possible and has been done */
                 if (actual == -ERESTARTSYS) {
@@ -501,7 +499,7 @@ static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
                         __FILE__,__LINE__, count);
                 
         /* This can happen if stuff comes in on the backup tty */
-        if (n_hdlc == 0 || tty != n_hdlc->tty)
+        if (!n_hdlc || tty != n_hdlc->tty)
                 return;
                 
         /* verify line is using HDLC discipline */
@@ -578,26 +576,36 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
                 return -EFAULT;
         }
 
+        lock_kernel();
+
         for (;;) {
-                if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+                if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+                        unlock_kernel();
                         return -EIO;
+                }
 
                 n_hdlc = tty2n_hdlc (tty);
                 if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
-                         tty != n_hdlc->tty)
+                         tty != n_hdlc->tty) {
+                        unlock_kernel();
                         return 0;
+                }
 
                 rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
                 if (rbuf)
                         break;
                         
                 /* no data */
-                if (file->f_flags & O_NONBLOCK)
+                if (file->f_flags & O_NONBLOCK) {
+                        unlock_kernel();
                         return -EAGAIN;
+                }
                         
                 interruptible_sleep_on (&tty->read_wait);
-                if (signal_pending(current))
+                if (signal_pending(current)) {
+                        unlock_kernel();
                         return -EINTR;
+                }
         }
                 
         if (rbuf->count > nr)
@@ -618,7 +626,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
                 kfree(rbuf);
         else    
                 n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf);
-        
+        unlock_kernel();
         return ret;
         
 }       /* end of n_hdlc_tty_read() */
@@ -661,6 +669,8 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
                 count = maxframe;
         }
         
+        lock_kernel();
+
         add_wait_queue(&tty->write_wait, &wait);
         set_current_state(TASK_INTERRUPTIBLE);
         
@@ -695,7 +705,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
                 n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf);
                 n_hdlc_send_frames(n_hdlc,tty);
         }
-
+        unlock_kernel();
         return error;
         
 }       /* end of n_hdlc_tty_write() */
@@ -740,8 +750,7 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
 
         case TIOCOUTQ:
                 /* get the pending tx byte count in the driver */
-                count = tty->driver->chars_in_buffer ?
-                                tty->driver->chars_in_buffer(tty) : 0;
+                count = tty_chars_in_buffer(tty);
                 /* add size of next output frame in queue */
                 spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock,flags);
                 if (n_hdlc->tx_buf_list.head)