Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 87108bc9 authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
Browse files

tty: n_tty: fix SIGIO for output 



According to fcntl(2), "a SIGIO signal is sent whenever input
or output becomes possible on that file descriptor", i.e.
after the output buffer was full and now has space for new data.
But in fact SIGIO is sent after every write.

n_tty_write() should set TTY_DO_WRITE_WAKEUP only when
not all data could be written to the buffer.

[pjh: Also fixes missed SIGIO if amt written just happens to be
[     amount still to write

Signed-off-by: default avatarJohannes Stezenbach <js@sig21.net>
[pjh: minor patch edits and re-submit]

Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ffb91a45

drivers/tty/n_tty.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -2361,7 +2361,7 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, 
	}

	}

break_out:

break_out:

	remove_wait_queue(&tty->write_wait, &wait);

	remove_wait_queue(&tty->write_wait, &wait);

	if (b - buf != nr && tty->fasync)

	if (nr && tty->fasync)

		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

	up_read(&tty->termios_rwsem);

	up_read(&tty->termios_rwsem);

	return (b - buf) ? b - buf : retval;

	return (b - buf) ? b - buf : retval;