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| author | ed <ed@FreeBSD.org> | 2009-12-01 19:14:57 +0000 |
|---|---|---|
| committer | ed <ed@FreeBSD.org> | 2009-12-01 19:14:57 +0000 |
| commit | 72b5ea2c05e0379e9c44721a12a9e1ede765941c (patch) | |
| tree | de36d426aab828904e4584369a2db9411f0f1c21 /sys/kern/tty.c | |
| parent | 8116463c117204a8a71a275eb1ffe266fa350954 (diff) | |
| download | FreeBSD-src-72b5ea2c05e0379e9c44721a12a9e1ede765941c.zip FreeBSD-src-72b5ea2c05e0379e9c44721a12a9e1ede765941c.tar.gz | |
Don't allocate an input buffer for a TTY when the receiver is turned off.
When the termios CREAD flag is not set, it makes little sense to
allocate an input buffer. Just set the size to 0 in this case to reduce
memory footprint.
Disallow CREAD to be disabled for pseudo-devices to prevent
foot-shooting.
Diffstat (limited to 'sys/kern/tty.c')
| -rw-r--r-- | sys/kern/tty.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/sys/kern/tty.c b/sys/kern/tty.c index 7e6cf00..9ef095c 100644 --- a/sys/kern/tty.c +++ b/sys/kern/tty.c @@ -102,10 +102,11 @@ static const char *dev_console_filename; static void tty_watermarks(struct tty *tp) { - size_t bs; + size_t bs = 0; /* Provide an input buffer for 0.2 seconds of data. */ - bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX); + if (tp->t_termios.c_cflag & CREAD) + bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX); ttyinq_setsize(&tp->t_inq, tp, bs); /* Set low watermark at 10% (when 90% is available). */ @@ -890,6 +891,7 @@ ttydevsw_defparam(struct tty *tp, struct termios *t) t->c_ospeed = B50; else if (t->c_ospeed > B115200) t->c_ospeed = B115200; + t->c_cflag |= CREAD; return (0); } |
