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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 5D13DC43603 for ; Tue, 17 Dec 2019 08:27:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3182A206EC for ; Tue, 17 Dec 2019 08:27:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576571260; bh=J4s2ewuYtJ4zzBG2WZm8IafXqFIzdyb19gjfIBR6qFg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=0wEeK3BtUDCI6KewPB96e+BetnOwic5JfpqhXiL5D07lIg0FyDdBnuo/WC99tWXT/ J0+305FpYSb+PyBwUxrVR4EUa0v7fOI111Plm9jU8Lt/cqAkMNzsb8UXIZY6R7CzWR RpsE9WxJ/DxqbfjRHPAJivJUIsjFjHtHIeZf24K8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725893AbfLQI1g (ORCPT ); Tue, 17 Dec 2019 03:27:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:37032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725769AbfLQI1g (ORCPT ); Tue, 17 Dec 2019 03:27:36 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AE827206EC; Tue, 17 Dec 2019 08:27:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576571255; bh=J4s2ewuYtJ4zzBG2WZm8IafXqFIzdyb19gjfIBR6qFg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iTJBmn0mlqnWNIyyfp8P0iIY5R3J3cZpr3kVsoRLzF8l72T00Y9xbj1kLb7DPHdPy 8/ANAfmgnCm7m2vnWawKtx/x3AiQd4KmithTlN4cl2L/w6PyueBTGiuHqf8hPQCiBE Wh8R1aRcQZIg7gKOCCjDHkxGPzhBXD2nDizx9hxs= Date: Tue, 17 Dec 2019 09:27:33 +0100 From: Greg Kroah-Hartman To: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Cc: Jacek Anaszewski , Pavel Machek , Dan Murphy , Jiri Slaby , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, linux-serial@vger.kernel.org, kernel@pengutronix.de Subject: Re: [PATCH v2 1/3] tty: new helper function tty_kopen_shared Message-ID: <20191217082733.GA2672708@kroah.com> References: <20191217081718.23807-1-u.kleine-koenig@pengutronix.de> <20191217081718.23807-2-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191217081718.23807-2-u.kleine-koenig@pengutronix.de> Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Tue, Dec 17, 2019 at 09:17:16AM +0100, Uwe Kleine-König wrote: > This function gives a struct tty_struct for a given device number. That says _what_ this does, but not why :) > > Signed-off-by: Uwe Kleine-König > --- > drivers/tty/tty_io.c | 27 +++++++++++++++++++++++++++ > include/linux/tty.h | 1 + > 2 files changed, 28 insertions(+) > > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > index d9f54c7d94f2..584025117cd3 100644 > --- a/drivers/tty/tty_io.c > +++ b/drivers/tty/tty_io.c > @@ -1925,6 +1925,33 @@ struct tty_struct *tty_kopen(dev_t device) > } > EXPORT_SYMBOL_GPL(tty_kopen); > > +/* > + * Caller gets a reference on (non-error) ttys, that must be disposed using > + * tty_kref_put(). > + */ It's a global function, can you please use kerneldoc? And please describe it as well as tty_kopen() is. > +struct tty_struct *tty_kopen_shared(dev_t device) > +{ > + struct tty_struct *tty; > + struct tty_driver *driver; > + int index = -1; > + > + mutex_lock(&tty_mutex); > + driver = tty_lookup_driver(device, NULL, &index); > + if (IS_ERR(driver)) { > + tty = ERR_CAST(driver); > + goto err_lookup_driver; > + } > + > + tty = tty_driver_lookup_tty(driver, NULL, index); No error check? > + > + tty_driver_kref_put(driver); > +err_lookup_driver: > + > + mutex_unlock(&tty_mutex); > + return tty; Can't you share a lot of this code with tty_kopen()? It feels odd to duplicatate _almost_ all of it here. > +} > +EXPORT_SYMBOL(tty_kopen_shared); EXPORT_SYMBOL_GPL() please. thanks, greg k-h