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 492B1E8181C for ; Tue, 26 Sep 2023 04:47:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233617AbjIZEr3 (ORCPT ); Tue, 26 Sep 2023 00:47:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbjIZEr0 (ORCPT ); Tue, 26 Sep 2023 00:47:26 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2045FB8; Mon, 25 Sep 2023 21:47:20 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2282C433C8; Tue, 26 Sep 2023 04:47:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695703639; bh=AMClMXoW/SwY9XBZNSxgkg0YbclLYYx39/FwqmsD/P4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rkUPrDB0Sc8Aa13mYevbDJwYR3shwPRBPjo91IL8D7otbra6/ar4Agns76mXyoPXl eeLGRc3tuiE7WXxMCDYBWAQpvPaTcUqMM658ZkEJ/Mn3e0EzkKCRsBGeBPc1/c+lE0 m3yODV1yBiXYk1aszHeoF3KWwDedd6Iw704oDQ8E= Date: Tue, 26 Sep 2023 06:47:16 +0200 From: Greg KH To: Yajun Deng Cc: Tony Nguyen , Jacob Keller , jesse.brandeburg@intel.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, richardcochran@gmail.com, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] i40e: fix the wrong PTP frequency calculation Message-ID: <2023092641-rind-seventh-c99b@gregkh> References: <20230627022658.1876747-1-yajun.deng@linux.dev> <10269e86-ed8a-0b09-a39a-a5239a1ba744@intel.com> <72bfc00f-7c60-f027-61cb-03084021c218@linux.dev> <9e1b824f-04d3-4acb-66d3-a5f90afbad0e@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 26, 2023 at 09:54:29AM +0800, Yajun Deng wrote: > > On 2023/9/26 07:59, Tony Nguyen wrote: > > On 9/25/2023 12:55 AM, Yajun Deng wrote: > > > > > > On 2023/6/28 04:20, Jacob Keller wrote: > > > > > > > > On 6/26/2023 7:26 PM, Yajun Deng wrote: > > > > > The new adjustment should be based on the base frequency, not the > > > > > I40E_PTP_40GB_INCVAL in i40e_ptp_adjfine(). > > > > > > > > > > This issue was introduced in commit 3626a690b717 ("i40e: use > > > > > mul_u64_u64_div_u64 for PTP frequency calculation"), and was fixed in > > > > > commit 1060707e3809 ("ptp: introduce helpers to adjust by scaled > > > > > parts per million"). However the latter is a new feature and > > > > > hasn't been > > > > > backported to the stable releases. > > > > > > > > > > This issue affects both v6.0 and v6.1 versions, and the v6.1 > > > > > version is > > > > > an LTS version. > > > > > > > > > ... > > > > > > > > > > Thanks for finding and fixing this mistake. I think its the > > > > simplest fix > > > > to get into the stable kernel that are broken, since taking the > > > > adjust_by_scaled_ppm version would require additional patches. > > > > > > > > Reviewed-by: Jacob Keller > > > > > > > Kindly ping... > > > > As this patch looks to be for stable, you need to follow the process for > > that. I believe your situation would fall into option 3: > > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-3 > > > > > Yes, it needs an upstream commit ID. But this patch didn't need to apply to > the upstream. > > As the commit of the patch, the issue was fixed in > commit 1060707e3809 ("ptp: introduce helpers to adjust by scaled > parts per million"). However the commit is a new feature and hasn't been > backported to the stable releases. > > Therefore, the patch does not have an upstream commit ID, and only needs to > be applied to stable. That wasn't very obvious to most of us, perhaps resend it and explicitly ask for acks/reviews so it can be only applied to the 6.1.y tree? thanks, greg k-h