From: Zhenguo Zhao Zhenguo.Zhao1@unisoc.com
[ Upstream commit cbff2b32516881bef30bbebf413d1b49495bab1d ]
When n_gsm config "initiator=0",as requester ,it doesn't need to send SABM frame data during gsmtty open.
Example,when gsmtty open,it will send SABM frame.for initiator,it maybe not want to receive the frame.
[ 88.410426] c1 gsmld_output: 00000000: f9 07 3f 01 de f9 [ 88.420839] c1 --> 1) R: SABM(F)
Signed-off-by: Zhenguo Zhao Zhenguo.Zhao1@unisoc.com Link: https://lore.kernel.org/r/1629461872-26965-6-git-send-email-zhenguo6858@gmai... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/n_gsm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 4946a241e323..f86c5ebfcf91 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -3214,6 +3214,7 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) { struct gsm_dlci *dlci = tty->driver_data; struct tty_port *port = &dlci->port; + struct gsm_mux *gsm = dlci->gsm;
port->count++; tty_port_tty_set(port, tty); @@ -3223,7 +3224,8 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) a DM straight back. This is ok as that will have caused a hangup */ tty_port_set_initialized(port, 1); /* Start sending off SABM messages */ - gsm_dlci_begin_open(dlci); + if (gsm->initiator) + gsm_dlci_begin_open(dlci); /* And wait for virtual carrier */ return tty_port_block_til_ready(port, tty, filp); }