tree f7200d98ecaa899fb2c83d6b58b88a20b302f936
parent a630fbfbb1beeffc5bbe542a7986bf2068874633
author Peter Hurley <peter@hurleysoftware.com> 1371295708 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1371498911 -0700

n_tty: Encapsulate minimum_to_wake within N_TTY

minimum_to_wake is unique to N_TTY processing, and belongs in
per-ldisc data.

Add the ldisc method, ldisc_ops::fasync(), to notify line disciplines
when signal-driven I/O is enabled or disabled. When enabled for N_TTY
(by fcntl(F_SETFL, O_ASYNC)), blocking reader/polls will be woken
for any readable input. When disabled, blocking reader/polls are not
woken until the read buffer is full.

Canonical mode (L_ICANON(tty), n_tty_data::icanon) is not affected by
the minimum_to_wake setting.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>