On https://bugs.launchpad.net/ubuntu/+source/linux/+bug/636091, one of
the cases reported is a big timeout on option_send_setup, which causes
some side effects as tty_lock is held. Looks like some of ZTE MF626
devices also don't like the RTS/DTR setting in option_send_setup, like
with 4G XS Stick W14. The reporter confirms which this it solves the
long freezes in his system.
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>