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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 01/20] tty: n_gsm: fix missing mux reset on config change at responder
Date:   Thu, 14 Apr 2022 02:42:06 -0700
Message-Id: <20220414094225.4527-1-daniel.starke@siemens.com>
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From: Daniel Starke <daniel.starke@siemens.com>

Currently, only the initiator resets the mux protocol if the user requests
new parameters that are incompatible to those of the current connection.
The responder also needs to reset the multiplexer if the new parameter set
requires this. Otherwise, we end up with an inconsistent parameter set
between initiator and responder.
Revert the old behavior to inform the peer upon an incompatible parameter
set change from the user on the responder side by re-establishing the mux
protocol in such case.

Fixes: 509067bbd264 ("tty: n_gsm: Delete gsm_disconnect when config requester")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
---
 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 fa92f727fdf8..3d28ecebd473 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2373,7 +2373,7 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c)
 	 * configuration
 	 */
 
-	if (gsm->initiator && (need_close || need_restart)) {
+	if (need_close || need_restart) {
 		int ret;
 
 		ret = gsm_disconnect(gsm);
-- 
2.25.1