• Sascha Hauer's avatar
    tty: n_gsm: do not send/receive in ldisc close path · 71e07791
    Sascha Hauer authored
    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: default avatarSascha Hauer <s.hauer@pengutronix.de>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    71e07791
n_gsm.c 78.1 KB