linux/Documentation/serial
Sascha Hauer 71e0779153 tty: n_gsm: do not send/receive in ldisc close path
gsm_cleanup_mux() is called in the line discipline close path which
is called at tty_release() time. At this stage the tty is no longer
operational enough to send any frames. Sending close frames is
therefore not possible and waiting for their answers always times
out.

This patch removes sending close messages and waiting for their answers
from the tty_release path.

This patch makes explicit what previously implicitly had been the case
already: We are not able to tell the modem that we are about to close
the multiplexer on our side. This means the modem will stay in
multiplexer mode and re-establishing the multiplexer later fails. The
only way for userspace to work around this is to manually send a close
frame in N_TTY mode after closing the mux.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:48:52 +09:00
..
00-INDEX Documentation/serial: Delete obsolete driver documentation 2014-04-16 14:20:34 -07:00
driver serial: doc: Use port->state instead of info 2016-05-14 10:18:25 -06:00
moxa-smartio
n_gsm.txt tty: n_gsm: do not send/receive in ldisc close path 2017-06-03 18:48:52 +09:00
README.cycladesZ
rocket.txt Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
serial-rs485.txt Documentation: rs485: Do not define manually the ioctl 2016-08-18 11:08:33 -06:00
tty.txt Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00

The Cyclades-Z must have firmware loaded onto the card before it will
operate.  This operation should be performed during system startup,

The firmware, loader program and the latest device driver code are
available from Cyclades at
    ftp://ftp.cyclades.com/pub/cyclades/cyclades-z/linux/