Prepare for special handling of pty throttle/unthrottle; factor
flow control into helper functions.
Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/n_tty.c | 81 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 46 insertions(+), 35 deletions(-)
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index d905b45..7f3509d 100644
--- 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
@@ -1509,21 +1553,7 @@ 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,
@@ -2067,26 +2097,7 @@ 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;
--
1.8.1.2
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