From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83EC9C3A5A1 for ; Thu, 22 Aug 2019 19:28:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5195021848 for ; Thu, 22 Aug 2019 19:28:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=geanix.com header.i=@geanix.com header.b="AQGCP9PW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732819AbfHVT2g (ORCPT ); Thu, 22 Aug 2019 15:28:36 -0400 Received: from first.geanix.com ([116.203.34.67]:38000 "EHLO first.geanix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729212AbfHVT2g (ORCPT ); Thu, 22 Aug 2019 15:28:36 -0400 Received: from [192.168.8.20] (unknown [85.184.140.241]) by first.geanix.com (Postfix) with ESMTPSA id 3A9B7370; Thu, 22 Aug 2019 19:28:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=geanix.com; s=first; t=1566502098; bh=o0N23vVITz0AcDJVlteTm0d45DuNdQ7fesle34nmy2M=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=AQGCP9PWjKUmzXyfL+ALCMEjmtrUqyJnWzGTyYpHoXZCurvuNpLwWPeYORkdeJgQl A5E6u/EMuTQl5t9ygY7USJwTp567meifDTmVSMViuAmUFvHc7LzS4pNVj4A9H84f4j ez1ykp3vbvM/uPadEuzfl48Y4ho037JCZY+fYuZdoxzsQFHl/JQ8hSsPmq3NSMMCcZ wwPxvyZMucP/xcUXx9PAIQleGFrDu6+WOSlM4iqeNHNFdMv1ugBSe/72La2iOQcBGi ga/OfEkTGLkkBL/G8GtB7CLfIuMrMNHC6IWtgV66U1OpDD3X2EH19HX4f8OGDGSaMO qZd9PGfR6KbJA== Subject: Re: [PATCHv4] tty: n_gsm: add ioctl to map serial device to mux'ed tty To: Greg Kroah-Hartman , Jiri Slaby , Alan Cox , linux-kernel@vger.kernel.org Cc: =?UTF-8?Q?Sean_Nyekj=c3=a6r?= , Esben Haabendal References: <20190812211243.98686-1-martin@geanix.com> From: =?UTF-8?Q?Martin_Hundeb=c3=b8ll?= Message-ID: Date: Thu, 22 Aug 2019 21:28:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190812211243.98686-1-martin@geanix.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US-large Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, Just a friendly "ping" on this patch. Thanks, Martin On 12/08/2019 23.12, Martin Hundebøll wrote: > Guessing the first tty for a gsm0710 multiplexed serial device is not > currently possible, which makes it racy to use with multiple modems. > > Add a way to map the physical serial tty to its related mux devices > using an ioctl. > > Signed-off-by: Martin Hundebøll > --- > > Changes since v3: > * use __u32 instead of uint32_t > > Changes since v2: > * rename IOCTL from GSMIOC_GETBASE to GSMIOC_GETFIRST > * return first usable line instead of private control line > * return uint32_t instead of int > > Changes since v1: > * use put_user() instead of copy_to_user() > * add missing opening quote > > Documentation/driver-api/serial/n_gsm.rst | 11 +++++++++-- > drivers/tty/n_gsm.c | 4 ++++ > include/uapi/linux/gsmmux.h | 2 ++ > 3 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/Documentation/driver-api/serial/n_gsm.rst b/Documentation/driver-api/serial/n_gsm.rst > index 0ba731ab00b2..286e7ff4d2d9 100644 > --- a/Documentation/driver-api/serial/n_gsm.rst > +++ b/Documentation/driver-api/serial/n_gsm.rst > @@ -18,10 +18,13 @@ How to use it > 2. switch the serial line to using the n_gsm line discipline by using > TIOCSETD ioctl, > 3. configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl, > +4. obtain base gsmtty number for the used serial port, > > Major parts of the initialization program : > (a good starting point is util-linux-ng/sys-utils/ldattach.c):: > > + #include > + #include > #include > #include > #define DEFAULT_SPEED B115200 > @@ -30,6 +33,7 @@ Major parts of the initialization program : > int ldisc = N_GSM0710; > struct gsm_config c; > struct termios configuration; > + uint32_t first; > > /* open the serial port connected to the modem */ > fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY); > @@ -58,19 +62,22 @@ Major parts of the initialization program : > c.mtu = 127; > /* set the new configuration */ > ioctl(fd, GSMIOC_SETCONF, &c); > + /* get first gsmtty device node */ > + ioctl(fd, GSMIOC_GETFIRST, &first); > + printf("first muxed line: /dev/gsmtty%i\n", first); > > /* and wait for ever to keep the line discipline enabled */ > daemon(0,0); > pause(); > > -4. use these devices as plain serial ports. > +5. use these devices as plain serial ports. > > for example, it's possible: > > - and to use gnokii to send / receive SMS on ttygsm1 > - to use ppp to establish a datalink on ttygsm2 > > -5. first close all virtual ports before closing the physical port. > +6. first close all virtual ports before closing the physical port. > > Note that after closing the physical port the modem is still in multiplexing > mode. This may prevent a successful re-opening of the port later. To avoid > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > index a60be591f1fc..d30525946892 100644 > --- a/drivers/tty/n_gsm.c > +++ b/drivers/tty/n_gsm.c > @@ -2613,6 +2613,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file, > { > struct gsm_config c; > struct gsm_mux *gsm = tty->disc_data; > + unsigned int base; > > switch (cmd) { > case GSMIOC_GETCONF: > @@ -2624,6 +2625,9 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file, > if (copy_from_user(&c, (void *)arg, sizeof(c))) > return -EFAULT; > return gsm_config(gsm, &c); > + case GSMIOC_GETFIRST: > + base = mux_num_to_base(gsm); > + return put_user(base + 1, (__u32 __user *)arg); > default: > return n_tty_ioctl_helper(tty, file, cmd, arg); > } > diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h > index 101d3c469acb..cb8693b39cb7 100644 > --- a/include/uapi/linux/gsmmux.h > +++ b/include/uapi/linux/gsmmux.h > @@ -37,5 +37,7 @@ struct gsm_netconfig { > #define GSMIOC_ENABLE_NET _IOW('G', 2, struct gsm_netconfig) > #define GSMIOC_DISABLE_NET _IO('G', 3) > > +/* get the base tty number for a configured gsmmux tty */ > +#define GSMIOC_GETFIRST _IOR('G', 4, __u32) > > #endif >