n_tty: Factor throttle/unthrottle into helper functions

Prepare for special handling of pty throttle/unthrottle; factor
flow control into helper functions.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 9ec0c68aa7396c4a46be620ffadbc5f27b1b998a..9e13c804ae723e29e92912e0f1a6d2e80c7e2721 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -214,6 +214,50 @@ static ssize_t chars_in_buffer(struct tty_struct *tty)
        return n;
 }
 
+static inline void n_tty_check_throttle(struct tty_struct *tty)
+{
+       /*
+        * Check the remaining room for the input canonicalization
+        * mode.  We don't want to throttle the driver if we're in
+        * canonical mode and don't have a newline yet!
+        */
+       while (1) {
+               int throttled;
+               tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
+               if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE)
+                       break;
+               throttled = tty_throttle_safe(tty);
+               if (!throttled)
+                       break;
+       }
+       __tty_set_flow_change(tty, 0);
+}
+
+static inline void n_tty_check_unthrottle(struct tty_struct *tty)
+{
+       /* If there is enough space in the read buffer now, let the
+        * low-level driver know. We use chars_in_buffer() to
+        * check the buffer, as it now knows about canonical mode.
+        * Otherwise, if the driver is throttled and the line is
+        * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
+        * we won't get any more characters.
+        */
+
+       while (1) {
+               int unthrottled;
+               tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
+               if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
+                       break;
+               if (!tty->count)
+                       break;
+               n_tty_set_room(tty);
+               unthrottled = tty_unthrottle_safe(tty);
+               if (!unthrottled)
+                       break;
+       }
+       __tty_set_flow_change(tty, 0);
+}
+
 /**
  *     put_tty_queue           -       add character to tty
  *     @c: character
@@ -1508,21 +1552,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
                        wake_up_interruptible(&tty->read_wait);
        }
 
-       /*
-        * Check the remaining room for the input canonicalization
-        * mode.  We don't want to throttle the driver if we're in
-        * canonical mode and don't have a newline yet!
-        */
-       while (1) {
-               int throttled;
-               tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
-               if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE)
-                       break;
-               throttled = tty_throttle_safe(tty);
-               if (!throttled)
-                       break;
-       }
-       __tty_set_flow_change(tty, 0);
+       n_tty_check_throttle(tty);
 }
 
 static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
@@ -2069,26 +2099,7 @@ do_it_again:
                        }
                }
 
-               /* If there is enough space in the read buffer now, let the
-                * low-level driver know. We use chars_in_buffer() to
-                * check the buffer, as it now knows about canonical mode.
-                * Otherwise, if the driver is throttled and the line is
-                * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
-                * we won't get any more characters.
-                */
-               while (1) {
-                       int unthrottled;
-                       tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
-                       if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
-                               break;
-                       if (!tty->count)
-                               break;
-                       n_tty_set_room(tty);
-                       unthrottled = tty_unthrottle_safe(tty);
-                       if (!unthrottled)
-                               break;
-               }
-               __tty_set_flow_change(tty, 0);
+               n_tty_check_unthrottle(tty);
 
                if (b - buf >= minimum)
                        break;