From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49v3KOvm3DIy8Oqsx9XRqzJRfhsa5j5FsrdHWGfbFadrPE5y7FCdV4CkqNX93+tA0A8HnD2 ARC-Seal: i=1; a=rsa-sha256; t=1523121602; cv=none; d=google.com; s=arc-20160816; b=VSgby86Ov7iDrVZ+4PQ4VkO+KGWC1J5ErHL+26GkxGmK7/hJofOmlnLzRUo7Aqw4nU czFU3kk71YbyLBM8yuc6wbpq08ohS1FObTyFP7DJyoMdQEKcVqCBvlrt7wa7BiiaQY5Y UjdTAdgRRvU/HWwVmSTpxdrppy891vSYQAqnYKgG2YvKnaI8MmsFLmu6me8Rm6lTJo7e Fdz+ghBanzr0bAGb3l1CyrZZP4oyVRrzqCall14+sXOHbo1FaQp8TA5fg1bE6d6vLJCV 2Q5GqaMgJicNFqVef45mzon32vlMLsYPcvO/MJx+ed2jNbxFxvaD6e3LdMqTLnSLCQPj IjWw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :arc-authentication-results; bh=KH56Gkfq7vwGQL1Tcvoy6BiLhwaCdQF8Gq5ACgos5ss=; b=NXvwQwruAacpLIOE8hZ4NOhcjgCu6TfqvKF5NTxN3tMoJ5TtCkBM+Mj3kVMIvoNxhP rc4PfYhLkJ1ypGNJmA3b+MmGb8p/vYkFmsDxRD1QIDIYPG9YEiY0iutIeZj4uhppsO7i MJHwqF+H7+4l02x6LPWTw54eS4a3mb8aC2tn73Cg+/JYQKs/r5zoczWxKkH7OQ82Lpl8 oiM/CHgiXdvBRCOdLCCIGisswM1HF8oH7yaz5ogyykXIX/czQ3J3qYwyHuz7yuQIirWQ zYHMUbWDe2VhryI6yTRVNt4A5VpfnMBMnTqbgVPbC4N2BuKthbkUOs3KdF1QL4H+j1aC jVkQ== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 72.249.23.125 is neither permitted nor denied by best guess record for domain of tony@atomide.com) smtp.mailfrom=tony@atomide.com Authentication-Results: mx.google.com; spf=neutral (google.com: 72.249.23.125 is neither permitted nor denied by best guess record for domain of tony@atomide.com) smtp.mailfrom=tony@atomide.com From: Tony Lindgren To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Alan Cox , Dan Williams , Jiri Prchal , Jiri Slaby , Marcel Partap , Merlijn Wajer , Michael Nazzareno Trimarchi , Michael Scott , Pavel Machek , Peter Hurley , Russ Gorby , Sascha Hauer , Sebastian Reichel Subject: [PATCH 2/2] tty: n_gsm: Fix DLCI handling for ADM mode if debug & 2 is not set Date: Sat, 7 Apr 2018 10:19:51 -0700 Message-Id: <20180407171951.122759-2-tony@atomide.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180407171951.122759-1-tony@atomide.com> References: <20180407171951.122759-1-tony@atomide.com> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597108757439873677?= X-GMAIL-MSGID: =?utf-8?q?1597108757439873677?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: At least on droid 4 with control channel in ADM mode, there is no response to Modem Status Command (MSC). Currently gsmtty_modem_update() expects to have data in dlci->modem_rx unless debug & 2 is set. This means that on droid 4, things only work if debug & 2 is set. Let's fix the issue by ignoring empty dlci->modem_rx for ADM mode. In the AMD mode, CMD_MSC will never respond and gsm_process_modem() won't get called to set dlci->modem_rx. And according to ts_127010v140000p.pdf, MSC is only relevant if basic option is chosen, so let's test for that too. Fixes: ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") Cc: linux-serial@vger.kernel.org Cc: Alan Cox Cc: Dan Williams Cc: Jiri Prchal Cc: Jiri Slaby Cc: Marcel Partap Cc: Merlijn Wajer Cc: Michael Nazzareno Trimarchi Cc: Michael Scott Cc: Pavel Machek Cc: Peter Hurley Cc: Russ Gorby Cc: Sascha Hauer Cc: Sebastian Reichel Signed-off-by: Tony Lindgren Cc: stable --- drivers/tty/n_gsm.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2871,11 +2871,22 @@ static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) static int gsm_carrier_raised(struct tty_port *port) { struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); + struct gsm_mux *gsm = dlci->gsm; + /* Not yet open so no carrier info */ if (dlci->state != DLCI_OPEN) return 0; if (debug & 2) return 1; + + /* + * Basic mode with control channel in ADM mode may not respond + * to CMD_MSC at all and modem_rx is empty. + */ + if (gsm->encoding == 0 && gsm->dlci[0]->mode == DLCI_MODE_ADM && + !dlci->modem_rx) + return 1; + return dlci->modem_rx & TIOCM_CD; } -- 2.17.0