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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BCB06CCD19A for ; Thu, 16 Oct 2025 08:02:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=epg/CJTop2yMwEwTNQzhdUDQRTPIOstndBbKQiZycUs=; b=lsCdpplCMdP3sZLgZM4/LlnH6G uiMEM95hQOEl6W20ZbhbMIXEMAemkqpD2krOzONIOu6lTh3N+HwlUD3xyb88Psnu8FrHDuk1/fQN3 w5vxCCyXCaKbeYmCS2wHx7bKraWWzBa/Ko2ycVPzTdsJdxckDIcYvQvmKng7Beoeso0Idqbe1AYNy Ts9Bitryzim5VyVXNMwehgSCTDBxSUOzCmrTEbIMMLCWTFCcKpXareMX8QFL9Yi9iBpPhEr2qoyt8 8TM4G8crCPBBlIvXrRSbb5MdH7k3wqjNiElz/NZTFgUufX1rqoa70rZmjowZnBgrNAPT9PPpCNacS eRD5OtXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v9IwC-00000003qOq-0w7a; Thu, 16 Oct 2025 08:02:16 +0000 Received: from smtpout-04.galae.net ([185.171.202.116]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v9Iw8-00000003qM2-2AKo for linux-arm-kernel@lists.infradead.org; Thu, 16 Oct 2025 08:02:15 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 75C80C03B71; Thu, 16 Oct 2025 08:01:50 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 94D946062C; Thu, 16 Oct 2025 08:02:09 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id ADF8C102F22F8; Thu, 16 Oct 2025 10:01:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1760601724; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:content-language:in-reply-to:references; bh=epg/CJTop2yMwEwTNQzhdUDQRTPIOstndBbKQiZycUs=; b=R86uQbSwPtfWBGs3P9qIkZwbYZIxEbHPKPfBOUcKnU4E91PDHpMmVcCdfUM39MUUox04kQ G1R/ikQ+nU9LU6nWtmUTpv4+0kCjgzQSITC3ZJteHpc3136OMXJz8TxYWYczhU5h3UoXzW BJEud93vn7k6MKpWQYYfI+XBV9MNEioT9ansLB4lAk8o/g8NOBN5JMBmK1eoSfBQJDtfFE FMqRKBsa/avl4sAJxydw/fS9LGMQUqKMHF/RHU52F2e7G6wcOmVUfpvFOigddgk3DCjz+A HZVtwoZl1uyNj06dWK+wvEu1SCwYeGfgKYXxzcjzxABs+bbtI8WcH7GuXguVvA== Message-ID: <731e8fa7-465b-4470-9036-c59fea602c07@bootlin.com> Date: Thu, 16 Oct 2025 10:01:53 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next 3/3] net: ethtool: tsconfig: Re-configure hwtstamp upon provider change To: Kory Maincent Cc: Alexandre Torgue , Jose Abreu , Andrew Lunn , davem@davemloft.net, Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , Richard Cochran , Russell King , =?UTF-8?Q?Alexis_Lothor=C3=A9?= , Thomas Petazzoni , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20251015102725.1297985-1-maxime.chevallier@bootlin.com> <20251015102725.1297985-4-maxime.chevallier@bootlin.com> <20251015144526.23e55ee0@kmaincent-XPS-13-7390> From: Maxime Chevallier Content-Language: en-US In-Reply-To: <20251015144526.23e55ee0@kmaincent-XPS-13-7390> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251016_010212_743093_14006740 X-CRM114-Status: GOOD ( 16.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Köry, On 15/10/2025 14:45, Kory Maincent wrote: > On Wed, 15 Oct 2025 12:27:23 +0200 > Maxime Chevallier wrote: > >> When a hwprov timestamping source is changed, but without updating the >> timestamping parameters, we may want to reconfigure the timestamping >> source to enable the new provider. >> >> This is especially important if the same HW unit implements 2 providers, >> a precise and an approx one. In this case, we need to make sure we call >> the hwtstamp_set operation for the newly selected provider. > > This is a design choice. > Do we want to preserve the hwtstamp config if only the hwtstamp source is > changed from ethtool? > If we want to configure the new source to the old source config we will also > need to remove this condition: > https://elixir.bootlin.com/linux/v6.17.1/source/net/ethtool/tsconfig.c#L339 What I get from the ethtool output is that the ts config is per-source. Re-applying the old config to the new source may not work if the new one doesn't have the same capabilities. > > I do not really have a strong opinion on this, let's discuss which behavior we > prefer. Well if we want to support different timestamp providers provided by the same HW block (same MAC or even same PHY), then we need a way to notify the provider when the timestamp provider gets selected and unselected. Otherwise there's no way for the provider to know it has been re-enabled, unless we perform a config change at the same time. Maxime