From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZqMbfiRrrD3Tb4mivEvQqtwpMIXT3nnB6f+nNgFBnLIwGFICf+6MySgMdJPJ0tEiojkQEnC ARC-Seal: i=1; a=rsa-sha256; t=1525116384; cv=none; d=google.com; s=arc-20160816; b=NpIES9AXsZzeySglnFhJKlhmTDHvILUdOa8UPJgpA+sduslZ124r7QnUS3jOXFnIBb CgzaHjzrtCdHXk6h91VTs8g0m2fnEQ0LheWWMTc3+neeUE42ZB0UXZ2E53t9EYZljAks sV/NIcUP2LIT3wqnA8RnRnrdpeBloekOPdV7c8/KErVpCUxhaX3qS+2xajsWKPm87il4 Ud8EqUdlVRpV9FS1aajjlvxYDOkOJf9PUquj3C/X745cbg7r6Fvi0xbB8EOFFm6jX4/5 eG1PyePHe4IHsfX6YHSOMDIRZcgtO4t+hhijAzYg0a+COG5xgUV2zlSRVVNdyKY2TlL3 Vm/Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dmarc-filter:arc-authentication-results; bh=EGeAdcBhBxYXYPpOsmpE7/pUY6feaksDZZnGzJNZZ3E=; b=LLB7tE6JAN4yTvpZKE1ZZfDVmeESZl4Sf7ZmFLxjD5smP39JGVrndMGy1QM1y4dLdI lux8a9YrFs+HW0j8bCmbpKpe3GlKWuPZmFw/zXl2fQxbhvJFruP/v9029oEssbuWKqO3 eRKiz5WOP+62LPzWP5JPrNL7tW3z5dqm6cowogGwgrPhOH2EYIfWxHO5lu3+yCWyrkoP OHK3dTMljBBFJtdKuE59z6KL3dczzaYBdN8LXz8mk5T6Pv3Pr2FQVZsnw87G33sxPPKA 3yl/lLyUYXJ4pklzW90aBSGO1DNsRM/Ln1rg0fe8jjoQahWna5qBEC+2ayjUsSJCpYNk sdNQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0884722E01 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@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 , Tony Lindgren Subject: [PATCH 4.9 22/61] tty: n_gsm: Fix DLCI handling for ADM mode if debug & 2 is not set Date: Mon, 30 Apr 2018 12:24:25 -0700 Message-Id: <20180430183953.203892608@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180430183951.312721450@linuxfoundation.org> References: <20180430183951.312721450@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1599200279987877864?= X-GMAIL-MSGID: =?utf-8?q?1599200438144938972?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tony Lindgren commit b2d89ad9c9682e795ed6eeb9ed455789ad6cedf1 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2875,11 +2875,22 @@ static int gsmtty_modem_update(struct gs 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; }