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 B9A29C19F2D for ; Thu, 11 Aug 2022 08:07:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234312AbiHKIHd (ORCPT ); Thu, 11 Aug 2022 04:07:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234269AbiHKIHc (ORCPT ); Thu, 11 Aug 2022 04:07:32 -0400 Received: from fw2.prolan.hu (fw2.prolan.hu [193.68.50.107]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0DD090186 for ; Thu, 11 Aug 2022 01:07:29 -0700 (PDT) Received: from imsva.intranet.prolan.hu (imss.intranet.prolan.hu [10.254.254.252]) by fw2.prolan.hu (Postfix) with ESMTPS id 04F6C7F4F5; Thu, 11 Aug 2022 10:07:27 +0200 (CEST) Received: from imsva.intranet.prolan.hu (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E5CA334064; Thu, 11 Aug 2022 10:07:26 +0200 (CEST) Received: from imsva.intranet.prolan.hu (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CC7CE3405A; Thu, 11 Aug 2022 10:07:26 +0200 (CEST) Received: from fw2.prolan.hu (unknown [10.254.254.253]) by imsva.intranet.prolan.hu (Postfix) with ESMTPS; Thu, 11 Aug 2022 10:07:26 +0200 (CEST) Received: from atlas.intranet.prolan.hu (atlas.intranet.prolan.hu [10.254.0.229]) by fw2.prolan.hu (Postfix) with ESMTPS id A129A7F4F5; Thu, 11 Aug 2022 10:07:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=prolan.hu; s=mail; t=1660205246; bh=cWyqlT+JCwjd6Y7gqECvYiA53jRQfyFDngYd1di2DI0=; h=Date:Subject:To:CC:References:From:In-Reply-To:From; b=G4KczGK5KeA05GmngcT7eJ1VImnc64xqskT7WvB4KVlXH75FKBb7Q0MERZ1ENw8eo XToEB8/RVciP+7uQ+MUuMXlFvobW4ZdKX5oN1C+wtVSucyr9TVe7BqPdJYCWInUk77 CpbOLPhgu5qxuFncbD3HNsoxTWWtm6sHZLsSgEkaKN9BhjahSUgNaSzNBLQ7MhxljO thV+HS6GFA2xYFJtY3Vrqy+KswQxmG7TjMZ+M/hFpIOKvi9cUhuMBfM4wXjsi5jnlk 34kH+RceOSYAFsX8JwfbBKGZ0GHQYQe6dkoN2ZG8VF4w+B1zIR5bDP9IzXsy9w33ul PQnCOygea7tXQ== Received: from [10.254.7.28] (10.254.7.28) by atlas.intranet.prolan.hu (10.254.0.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P521) id 15.1.2507.9; Thu, 11 Aug 2022 10:07:25 +0200 Message-ID: Date: Thu, 11 Aug 2022 10:07:17 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH] fec: Restart PPS after link state change Content-Language: en-US To: Andrew Lunn , Richard Cochran CC: , Fugang Duan References: <20220809124119.29922-1-csokas.bence@prolan.hu> <299d74d5-2d56-23f6-affc-78bb3ae3e03c@prolan.hu> From: =?UTF-8?B?Q3PDs2vDoXMgQmVuY2U=?= In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.254.7.28] X-ClientProxiedBy: atlas.intranet.prolan.hu (10.254.0.229) To atlas.intranet.prolan.hu (10.254.0.229) X-EsetResult: clean, is OK X-EsetId: 37303A29971EF456617362 X-TM-AS-GCONF: 00 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2022. 08. 11. 4:05, Andrew Lunn wrote: > On Wed, Aug 10, 2022 at 06:37:19PM -0700, Richard Cochran wrote: >> On Thu, Aug 11, 2022 at 02:05:39AM +0200, Andrew Lunn wrote: >>>> Yes. We use PPS to synchronize devices on a common backplane. We use PTP to >>>> sync this PPS to a master clock. But if PTP sync drops out, we wouldn't want >>>> the backplane-level synchronization to fail. The PPS needs to stay on as >>>> long as userspace *explicitly* disables it, regardless of what happens to >>>> the link. >>> >>> We need the PTP Maintainers view on that. I don't know if that is >>> normal or not. >> >> IMO the least surprising behavior is that once enabled, a feature >> stays on until explicitly disabled. > > O.K, thanks for the response. > > Your answer is a bit surprising to me. To me, an interface which is > administratively down is completely inactive. The action to down it > should disable everything. I think you are confusing two states here. This patch addresses the bug thatcauses the PPS to drop when the Ethernet link goes away. The interface remainsUP the whole time. > > So your answer also implies PPS can be used before the interface is > set administratively up? The PPS can already be used before the first link-up, but once it has acquired a link once, PPS no longer works without a link. > > Andrew