From patchwork Mon Feb 6 11:46:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Starke" X-Patchwork-Id: 651209 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 048FAC61DA4 for ; Mon, 6 Feb 2023 11:48:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229664AbjBFLsB (ORCPT ); Mon, 6 Feb 2023 06:48:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229925AbjBFLrl (ORCPT ); Mon, 6 Feb 2023 06:47:41 -0500 Received: from mta-64-228.siemens.flowmailer.net (mta-64-228.siemens.flowmailer.net [185.136.64.228]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4150230E9 for ; Mon, 6 Feb 2023 03:47:40 -0800 (PST) Received: by mta-64-228.siemens.flowmailer.net with ESMTPSA id 20230206114738b9fcd7482b6f437ac3 for ; Mon, 06 Feb 2023 12:47:38 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=daniel.starke@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=domF8YVtcGEgafqQbH+2EimrKfYiC4Tyhq8j6uN7Cl8=; b=G3QSpwrViFPBEsQfV/TVUPLvxOREDjSYVk8g7XNjwMOmS4oV6KNiEwVvsfZsBCgyiW56aI pbynbUEVI3mVskAoKL3/KN7nBaGKLCmYoNAFVF4xuRGDKcajeJb9xH7iVaa3Clpt3Cn5QClk G1ONb7BIHH1A0kZ8FppdC2N0XBmFU=; From: "D. Starke" To: linux-serial@vger.kernel.org, gregkh@linuxfoundation.org, jirislaby@kernel.org, ilpo.jarvinen@linux.intel.com Cc: linux-kernel@vger.kernel.org, Daniel Starke Subject: [PATCH v4 4/4] tty: n_gsm: add TIOCMIWAIT support Date: Mon, 6 Feb 2023 12:46:06 +0100 Message-Id: <20230206114606.2133-4-daniel.starke@siemens.com> In-Reply-To: <20230206114606.2133-1-daniel.starke@siemens.com> References: <20230206114606.2133-1-daniel.starke@siemens.com> MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-314044:519-21489:flowmailer Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Daniel Starke Add support for the TIOCMIWAIT ioctl on the virtual ttys. This enables the user to wait for virtual modem signals like RING. More work is needed to support also TIOCGICOUNT. Signed-off-by: Daniel Starke --- drivers/tty/n_gsm.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) v3 -> v4: No changes. Link: https://lore.kernel.org/all/20230203145023.6012-4-daniel.starke@siemens.com/ diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 79efbfd27171..e405d76cb696 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1542,6 +1542,7 @@ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, if (brk & 0x01) tty_insert_flip_char(&dlci->port, 0, TTY_BREAK); dlci->modem_rx = mlines; + wake_up_interruptible(&dlci->gsm->event); } /** @@ -2129,7 +2130,7 @@ static void gsm_dlci_close(struct gsm_dlci *dlci) /* A DLCI 0 close is a MUX termination so we need to kick that back to userspace somehow */ gsm_dlci_data_kick(dlci); - wake_up(&dlci->gsm->event); + wake_up_all(&dlci->gsm->event); } /** @@ -2339,6 +2340,7 @@ static void gsm_dlci_begin_close(struct gsm_dlci *dlci) dlci->state = DLCI_CLOSING; gsm_command(dlci->gsm, dlci->addr, DISC|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); + wake_up_interruptible(&gsm->event); } /** @@ -3878,6 +3880,33 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) return -EPROTONOSUPPORT; } +/** + * gsm_wait_modem_change - wait for modem status line change + * @dlci: channel + * @mask: modem status line bits + * + * The function returns if: + * - any given modem status line bit changed + * - the wait event function got interrupted (e.g. by a signal) + * - the underlying DLCI was closed + * - the underlying ldisc device was removed + */ +static int gsm_wait_modem_change(struct gsm_dlci *dlci, u32 mask) +{ + struct gsm_mux *gsm = dlci->gsm; + u32 old = dlci->modem_rx; + int ret; + + ret = wait_event_interruptible(gsm->event, gsm->dead || + dlci->state != DLCI_OPEN || + (old ^ dlci->modem_rx) & mask); + if (gsm->dead) + return -ENODEV; + if (dlci->state != DLCI_OPEN) + return -EL2NSYNC; + return ret; +} + static bool gsm_carrier_raised(struct tty_port *port) { struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); @@ -4137,6 +4166,8 @@ static int gsmtty_ioctl(struct tty_struct *tty, gsm_destroy_network(dlci); mutex_unlock(&dlci->mutex); return 0; + case TIOCMIWAIT: + return gsm_wait_modem_change(dlci, (u32)arg); default: return -ENOIOCTLCMD; }