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From: "D. Starke" <daniel.starke@siemens.com>
To: linux-serial@vger.kernel.org, gregkh@linuxfoundation.org,
	jirislaby@kernel.org
Cc: linux-kernel@vger.kernel.org, Daniel Starke <daniel.starke@siemens.com>
Subject: [PATCH v4 7/9] tty: n_gsm: fix packet re-transmission without open control channel
Date: Fri,  1 Jul 2022 08:16:50 +0200	[thread overview]
Message-ID: <20220701061652.39604-7-daniel.starke@siemens.com> (raw)
In-Reply-To: <20220701061652.39604-1-daniel.starke@siemens.com>

From: Daniel Starke <daniel.starke@siemens.com>

In the current implementation control packets are re-transmitted even if
the control channel closed down during T2. This is wrong.
Check whether the control channel is open before re-transmitting any
packets. Note that control channel open/close is handled by T1 and not T2
and remains unaffected by this.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
---
 drivers/tty/n_gsm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Stable backport remark has been removed compared to v3. No other changes applied.

Link: https://lore.kernel.org/all/20220530144512.2731-7-daniel.starke@siemens.com/

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index b82efb63f4e6..9e4ada510c9f 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1624,7 +1624,7 @@ static void gsm_control_retransmit(struct timer_list *t)
 	spin_lock_irqsave(&gsm->control_lock, flags);
 	ctrl = gsm->pending_cmd;
 	if (ctrl) {
-		if (gsm->cretries == 0) {
+		if (gsm->cretries == 0 || !gsm->dlci[0] || gsm->dlci[0]->dead) {
 			gsm->pending_cmd = NULL;
 			ctrl->error = -ETIMEDOUT;
 			ctrl->done = 1;
-- 
2.34.1


  parent reply	other threads:[~2022-07-01  6:19 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-01  6:16 [PATCH v4 1/9] tty: n_gsm: fix user open not possible at responder until initiator open D. Starke
2022-07-01  6:16 ` [PATCH v4 2/9] tty: n_gsm: fix tty registration before control channel open D. Starke
2022-07-01  6:16 ` [PATCH v4 3/9] tty: n_gsm: fix wrong queuing behavior in gsm_dlci_data_output() D. Starke
2022-07-01  6:16 ` [PATCH v4 4/9] tty: n_gsm: fix missing timer to handle stalled links D. Starke
2022-07-01  6:16 ` [PATCH v4 5/9] tty: n_gsm: fix non flow control frames during mux flow off D. Starke
2022-07-01  6:16 ` [PATCH v4 6/9] tty: n_gsm: fix deadlock and link starvation in outgoing data path D. Starke
2022-07-01  6:16 ` D. Starke [this message]
2022-07-01  6:16 ` [PATCH v4 8/9] tty: n_gsm: fix resource allocation order in gsm_activate_mux() D. Starke
2022-07-01  6:16 ` [PATCH v4 9/9] tty: n_gsm: fix race condition in gsmld_write() D. Starke
2022-07-01  8:08 ` [PATCH v4 1/9] tty: n_gsm: fix user open not possible at responder until initiator open Greg KH

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