n_hdlc: honor O_NONBLOCK on write

Make n_hdlc line discipline honor the O_NONBLOCK file flag on write.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Paul Fulghum 2008-07-22 11:21:19 +01:00 committed by Linus Torvalds
parent 768aec0b5b
commit c72f527c10

View File

@ -677,6 +677,10 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
/* Allocate transmit buffer */
/* sleep until transmit buffer available */
while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
if (file->f_flags & O_NONBLOCK) {
error = -EAGAIN;
break;
}
schedule();
n_hdlc = tty2n_hdlc (tty);