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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5291CC05027 for ; Wed, 1 Feb 2023 08:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231781AbjBAIli (ORCPT ); Wed, 1 Feb 2023 03:41:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230200AbjBAIle (ORCPT ); Wed, 1 Feb 2023 03:41:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE5645C0EB; Wed, 1 Feb 2023 00:41:33 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 86D2FB8212D; Wed, 1 Feb 2023 08:41:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC08CC433D2; Wed, 1 Feb 2023 08:41:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675240891; bh=h6baFCsgm+aiCf/GL1i1K7HcEqSR8H51V6MXvVl0qYw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=L4oIpLMaGdwjJT8sCC3AWXmzBNj7HqZAGszoXkmoWF+z5yFMfTq1jSRg3BEuW7jEn Zqwv2zAOVXBF8PmTWA7wfzwOQOnbJcAnsr8QGFzTI0EDaYF1RJpEFacuZzdB3uTIrj OoSuBVlJ9dGEE9yGaPZQcCumM+K924AmmfFEFtvc= Date: Wed, 1 Feb 2023 09:41:28 +0100 From: Greg KH To: "D. Starke" Cc: linux-serial@vger.kernel.org, jirislaby@kernel.org, ilpo.jarvinen@linux.intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] tty: n_gsm: add TIOCMIWAIT support Message-ID: References: <20230201080151.2068-1-daniel.starke@siemens.com> <20230201080151.2068-3-daniel.starke@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230201080151.2068-3-daniel.starke@siemens.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 01, 2023 at 09:01:51AM +0100, D. Starke wrote: > 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. > > Signed-off-by: Daniel Starke > --- > drivers/tty/n_gsm.c | 32 ++++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > index 118511c1fa37..48fb7dad44cd 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); > } > > /** > @@ -3848,6 +3849,35 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) > return -EPROTONOSUPPORT; > } > > +/** > + * gsm_wait_modem_change - wait for modem status line change No need for tabs. Or for kernel doc for static functions, but that's not a big deal. > + * @dlci: channel > + * @mask: modem status line bits > + */ > + No blank line please, didn't checkpatch warn about that? > +static int gsm_wait_modem_change(struct gsm_dlci *dlci, u32 mask) > +{ > + struct gsm_mux *gsm = dlci->gsm; > + u32 old = dlci->modem_rx & mask; > + int ret; > + > + if (gsm->dead) > + return -ENODEV; > + > + do { > + ret = wait_event_interruptible(gsm->event, gsm->dead > + || old ^ (dlci->modem_rx & mask)); > + if (ret) > + return ret; > + if (dlci->state != DLCI_OPEN) > + return -EL2NSYNC; > + if (gsm->dead) > + return -ENODEV; > + } while ((old ^ (dlci->modem_rx & mask)) == 0); No way to break out of the loop if it goes for forever? thanks, greg k-h