n_tty: Simplify throttle threshold calculation
The adjustments performed by receive_room() are to ensure a line
termination can always be written to the read buffer. However,
these adjustments are irrelevant to the throttle threshold (because
the threshold < buffer limit).
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 d4b14c3..7efabc4 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -262,7 +262,7 @@
while (1) {
int throttled;
tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
- if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE)
+ if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE)
break;
throttled = tty_throttle_safe(tty);
if (!throttled)