From e5e39b524473d86b022b9d45e680f2a66626cb17 Mon Sep 17 00:00:00 2001 From: Daniel Starke Date: Thu, 7 Jul 2022 13:32:21 +0200 Subject: [PATCH] tty: n_gsm: fix DM command [ Upstream commit 18a948c7d90995d127785e308fa7b701df4c499f ] n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.3.3 defines the DM response. There exists no DM command. However, the current implementation incorrectly sends DM as command in case of unexpected UIH frames in gsm_queue(). Correct this behavior by always sending DM as response. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke Link: https://lore.kernel.org/r/20220707113223.3685-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/n_gsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 1a70e7ae90cc..90060018928f 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2207,7 +2207,7 @@ static void gsm_queue(struct gsm_mux *gsm) case UIH: case UIH|PF: if (dlci == NULL || dlci->state != DLCI_OPEN) { - gsm_command(gsm, address, DM|PF); + gsm_response(gsm, address, DM|PF); return; } dlci->data(dlci, gsm->buf, gsm->len);