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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 24513C433DF for ; Fri, 22 May 2020 17:13:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3813206D5 for ; Fri, 22 May 2020 17:13:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730782AbgEVRNW (ORCPT ); Fri, 22 May 2020 13:13:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730536AbgEVRNV (ORCPT ); Fri, 22 May 2020 13:13:21 -0400 Received: from hera.aquilenet.fr (hera.aquilenet.fr [IPv6:2a0c:e300::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A8B1C061A0E for ; Fri, 22 May 2020 10:13:21 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by hera.aquilenet.fr (Postfix) with ESMTP id 69A153968; Fri, 22 May 2020 19:13:17 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Received: from hera.aquilenet.fr ([127.0.0.1]) by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xn3rcvaificZ; Fri, 22 May 2020 19:13:15 +0200 (CEST) Received: from function (unknown [IPv6:2a01:cb19:956:1b00:9eb6:d0ff:fe88:c3c7]) by hera.aquilenet.fr (Postfix) with ESMTPSA id 7B3002E76; Fri, 22 May 2020 19:13:15 +0200 (CEST) Received: from samy by function with local (Exim 4.93) (envelope-from ) id 1jcBEO-00HA74-1l; Fri, 22 May 2020 19:13:12 +0200 Date: Fri, 22 May 2020 19:13:12 +0200 From: Samuel Thibault To: Joe Perches Cc: Dan Carpenter , MugilRaj , devel@driverdev.osuosl.org, Kirk Reiser , Greg Kroah-Hartman , speakup@linux-speakup.org, linux-kernel@vger.kernel.org, Chris Brannon Subject: Re: [PATCH] taging: speakup: remove volatile Message-ID: <20200522171312.s2ciifuxozwav2ym@function> Mail-Followup-To: Samuel Thibault , Joe Perches , Dan Carpenter , MugilRaj , devel@driverdev.osuosl.org, Kirk Reiser , Greg Kroah-Hartman , speakup@linux-speakup.org, linux-kernel@vger.kernel.org, Chris Brannon References: <1590138989-6091-1-git-send-email-dmugil2000@gmail.com> <20200522103406.GK30374@kadam> <6ab4139ec78928961a19e5fdbda139bb8cff9cb5.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6ab4139ec78928961a19e5fdbda139bb8cff9cb5.camel@perches.com> Organization: I am not organized User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Joe Perches, le ven. 22 mai 2020 09:36:05 -0700, a ecrit: > On Fri, 2020-05-22 at 13:34 +0300, Dan Carpenter wrote: > > On Fri, May 22, 2020 at 02:46:28PM +0530, MugilRaj wrote: > > > fix checkpatch.pl warning, which is Use of volatile is usually wrong: see > > > Documentation/process/volatile-considered-harmful.rst > > > Signed-off-by: MugilRaj > > > > Please put a blank before the Signed-off-by line. > > > > Probably there should be a space between your first and last name. It's > > supposed to your legal name like for signing a legal document so use > > whatever is appropriate legal documents in your country. > > > > Also the Documentation/process/volatile-considered-harmful.rst explains > > that people often use "volatile" when they should be using locking for > > synchronization. That seems to be the case here. So the correct fix is > > to add locking. That's a little bit complicated to do and requires > > testing. > > > > If we apply this patch, then we have silenced the warning so now someone > > will have to look for the bug. But if we leave it as-is, then everyone > > will know that the code is buggy. So let's leave it as-is until we are > > able to fix the bug. > > > > It's always better to have easy to find bugs, than hidden bugs. > > And better still to comment known opportunities to > improve the code so the next time someone tries to > remove this volatile, there's a comment right there > showing what's necessary instead. Actually I don't think adding the suggestion is a good thing if it's only a "rule-of-thumb-replace-volatile-with-lock". Actually possibly volatile might not even be needed because there could be already a lock protecting this. Put another way: I don't think putting any hint here would help, on the contrary, somebody has to really look at what protection is needed, without getting influenced by rules-of-thumb. Samuel 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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 0CC3EC433E0 for ; Fri, 22 May 2020 17:13:26 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C04B0206D5 for ; Fri, 22 May 2020 17:13:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C04B0206D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ens-lyon.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=driverdev-devel-bounces@linuxdriverproject.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 7A38225AE2; Fri, 22 May 2020 17:13:25 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id CDB5tfTRW5k4; Fri, 22 May 2020 17:13:23 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by silver.osuosl.org (Postfix) with ESMTP id 1237620532; Fri, 22 May 2020 17:13:23 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by ash.osuosl.org (Postfix) with ESMTP id 1204F1BF3BC for ; Fri, 22 May 2020 17:13:22 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 0B8FF88731 for ; Fri, 22 May 2020 17:13:22 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xt0GMhIIfqRE for ; Fri, 22 May 2020 17:13:21 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from hera.aquilenet.fr (hera.aquilenet.fr [185.233.100.1]) by whitealder.osuosl.org (Postfix) with ESMTPS id F3BCA81C8D for ; Fri, 22 May 2020 17:13:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hera.aquilenet.fr (Postfix) with ESMTP id 69A153968; Fri, 22 May 2020 19:13:17 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Received: from hera.aquilenet.fr ([127.0.0.1]) by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xn3rcvaificZ; Fri, 22 May 2020 19:13:15 +0200 (CEST) Received: from function (unknown [IPv6:2a01:cb19:956:1b00:9eb6:d0ff:fe88:c3c7]) by hera.aquilenet.fr (Postfix) with ESMTPSA id 7B3002E76; Fri, 22 May 2020 19:13:15 +0200 (CEST) Received: from samy by function with local (Exim 4.93) (envelope-from ) id 1jcBEO-00HA74-1l; Fri, 22 May 2020 19:13:12 +0200 Date: Fri, 22 May 2020 19:13:12 +0200 From: Samuel Thibault To: Joe Perches Subject: Re: [PATCH] taging: speakup: remove volatile Message-ID: <20200522171312.s2ciifuxozwav2ym@function> Mail-Followup-To: Samuel Thibault , Joe Perches , Dan Carpenter , MugilRaj , devel@driverdev.osuosl.org, Kirk Reiser , Greg Kroah-Hartman , speakup@linux-speakup.org, linux-kernel@vger.kernel.org, Chris Brannon References: <1590138989-6091-1-git-send-email-dmugil2000@gmail.com> <20200522103406.GK30374@kadam> <6ab4139ec78928961a19e5fdbda139bb8cff9cb5.camel@perches.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <6ab4139ec78928961a19e5fdbda139bb8cff9cb5.camel@perches.com> Organization: I am not organized User-Agent: NeoMutt/20170609 (1.8.3) X-BeenThere: driverdev-devel@linuxdriverproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Driver Project Developer List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devel@driverdev.osuosl.org, Kirk Reiser , Greg Kroah-Hartman , speakup@linux-speakup.org, linux-kernel@vger.kernel.org, MugilRaj , Dan Carpenter , Chris Brannon Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" Joe Perches, le ven. 22 mai 2020 09:36:05 -0700, a ecrit: > On Fri, 2020-05-22 at 13:34 +0300, Dan Carpenter wrote: > > On Fri, May 22, 2020 at 02:46:28PM +0530, MugilRaj wrote: > > > fix checkpatch.pl warning, which is Use of volatile is usually wrong: see > > > Documentation/process/volatile-considered-harmful.rst > > > Signed-off-by: MugilRaj > > > > Please put a blank before the Signed-off-by line. > > > > Probably there should be a space between your first and last name. It's > > supposed to your legal name like for signing a legal document so use > > whatever is appropriate legal documents in your country. > > > > Also the Documentation/process/volatile-considered-harmful.rst explains > > that people often use "volatile" when they should be using locking for > > synchronization. That seems to be the case here. So the correct fix is > > to add locking. That's a little bit complicated to do and requires > > testing. > > > > If we apply this patch, then we have silenced the warning so now someone > > will have to look for the bug. But if we leave it as-is, then everyone > > will know that the code is buggy. So let's leave it as-is until we are > > able to fix the bug. > > > > It's always better to have easy to find bugs, than hidden bugs. > > And better still to comment known opportunities to > improve the code so the next time someone tries to > remove this volatile, there's a comment right there > showing what's necessary instead. Actually I don't think adding the suggestion is a good thing if it's only a "rule-of-thumb-replace-volatile-with-lock". Actually possibly volatile might not even be needed because there could be already a lock protecting this. Put another way: I don't think putting any hint here would help, on the contrary, somebody has to really look at what protection is needed, without getting influenced by rules-of-thumb. Samuel _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel