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 BF1FFC433F5 for ; Tue, 28 Dec 2021 16:00:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235485AbhL1QAy (ORCPT ); Tue, 28 Dec 2021 11:00:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235480AbhL1QAy (ORCPT ); Tue, 28 Dec 2021 11:00:54 -0500 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF70FC061574 for ; Tue, 28 Dec 2021 08:00:53 -0800 (PST) Received: by mail-pj1-x1032.google.com with SMTP id y16-20020a17090a6c9000b001b13ffaa625so21971944pjj.2 for ; Tue, 28 Dec 2021 08:00:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=+EErxxyRGrc3fIcdCuA+M5TmuzvvFgyPQfNF+QKyEJA=; b=bypY8ngWBwcgkxdKMtgGYXT7/IQ6MPDnRPU3k2FPRYMvuHE/T/g5/vqEKlXAXxqXhl CwA9Iwd8GXMX2X0JZhYtE+1Y/Me3/NA2GV90YN5+YqRbLO2Rl0YcPw9VCnt5Ne1pQwDK hmK6xGdHcm8GAP48+QR8jfwsiE+9Nt6Xl9W9OSW30xr6eGd0xko4p+5vB0vRNZ/BEBB2 zGWXR+bzk7zsX7hEyjVdu/UP3H0gBsol7Lnry3o7obAQLrRQ24msI/SrONpBbbo+0NQv ZeyU591cQeTIbxx6UjOMnsij0HE/RtkBTCKJ0BvizDDNPhXTkcykHr6hlmVQACArUL+n vB2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=+EErxxyRGrc3fIcdCuA+M5TmuzvvFgyPQfNF+QKyEJA=; b=alT0XVjXdezbLe+zjLYIIXNkywp1PAjOhhvtdGRPHvhmTqabvGUR4oVpXlMoNvfOmN rBi1y1ARXYYIUQpKTt/FAAcIUqqgHzixg7nkzOIV5Ax6uSARLa2lDwwCOAhkcJMJ/dWD y1UWTCopTn/lE2wVr5Bp8JF6aUR8pdvRLPVpMLnCwXrtBhn2TPFlGcYySxqLqTrJUtc9 pbz8G64UNL3nqSOT7TS0UWmg05KIzzDOCNeFFvuYdV6k9U2ZN7+jg7dbCIb/PJvDi8tT YligklkRLECNgg5CcyGGo+sSVV+1OiBT+LEmx4Df2rrzx/SrvNLUd7Z5xO/WDp74jiVA WsqQ== X-Gm-Message-State: AOAM532XvXa631+WlAzR3e21bGT51WoS3ccnqJYrBqkFzg8RsRNLE9pV qpvSvwiGzM96nsFMWWgth7A= X-Google-Smtp-Source: ABdhPJyaFLrmxEzAEEKLqm3HuivOclWe8MAdl09XDL5dvVerhd+Ai2TOUa9lkRYCrYG57TikhPDU2g== X-Received: by 2002:a17:902:bb8c:b0:149:8f60:a526 with SMTP id m12-20020a170902bb8c00b001498f60a526mr4786862pls.25.1640707253239; Tue, 28 Dec 2021 08:00:53 -0800 (PST) Received: from hoboy.vegasvil.org ([2601:640:8200:33:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id y8sm22980755pjt.25.2021.12.28.08.00.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Dec 2021 08:00:52 -0800 (PST) Date: Tue, 28 Dec 2021 08:00:50 -0800 From: Richard Cochran To: Jakub Kicinski Cc: Hangbin Liu , netdev@vger.kernel.org, Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , "David S . Miller" , Heiner Kallweit Subject: Re: [PATCHv3 net-next 1/2] net_tstamp: add new flag HWTSTAMP_FLAG_BONDED_PHC_INDEX Message-ID: <20211228160050.GA13274@hoboy.vegasvil.org> References: <20211210085959.2023644-1-liuhangbin@gmail.com> <20211210085959.2023644-2-liuhangbin@gmail.com> <20211228071528.040fd3e3@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211228071528.040fd3e3@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Dec 28, 2021 at 07:15:28AM -0800, Jakub Kicinski wrote: > On Tue, 28 Dec 2021 15:01:13 +0800 Hangbin Liu wrote: > > When implement the user space support for this feature. I realized that > > we can't use the new flag directly as the user space tool needs to have > > backward compatibility. Because run the new tool with this flag enabled > > on old kernel will get -EINVAL error. And we also could not use #ifdef > > directly as HWTSTAMP_FLAG_BONDED_PHC_INDEX is a enum. > > > > Do you think if we could add a #define in linux/net_tstamp.h like > > > > #define HWTSTAMP_FLAGS_SUPPORT 1 > > > > So that the user space tool could use it like > > > > #ifdef HWTSTAMP_FLAGS_SUPPORT > > cfg->flags = HWTSTAMP_FLAG_BONDED_PHC_INDEX; > > #endif > > We could set it on SIOCGHWTSTAMP to let user space know that it's > necessary for a given netdev. What about adding matching #defines into the enum declaration? enum hwtstamp_flags { HWTSTAMP_FLAG_BONDED_PHC_INDEX = (1<<0), #define HWTSTAMP_FLAG_BONDED_PHC_INDEX (1<<0) }; IIRC I have seen this pattern used in the kernel, but ATM I can't find any example :( Thanks, Richard