From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B46024B29; Fri, 26 Jul 2024 19:04:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722020683; cv=none; b=NkpgnCy1QwXGN2AKB3ZZmerr8zdLR9wJHMpWnawJnBsmtcAwlNUsTjGRby/3m0SZY515aDzEmegAtq6UGbnmY1dEMoJWRFbWM7vG/Y8797YRgvDR/VMENxxDyAc29evAULPStnwRii13HI/VYWJM4jdwCyy//vIpnH4zQLdhPuY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722020683; c=relaxed/simple; bh=9aJvFjwGUsuHrwEO0EUiNoQjVM1etnRRAnje0PVOlXo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qqrgV8Y0Is8+q1nhvdxBkdDVBRna3c9eOU8CgKxhvtWK6JnrXv1f+7sn6os5HwEg1PsoDJB2Qljx3F/sMMvgBbDJ/C7bGl1sSu3H53B07ce4XmaWhNvNRU9GfdWlohmV2bYJwt+71KUV0J5zyhNNzdOBFecPhSybJ3Mg5cTg7Ac= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=A2P86hru; arc=none smtp.client-ip=217.70.183.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="A2P86hru" Received: by mail.gandi.net (Postfix) with ESMTPSA id 68D4140002; Fri, 26 Jul 2024 19:04:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1722020672; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CQhD1Kldwv4wUD10x0w7aNE1h2WOcAEA34mUy+q4KL0=; b=A2P86hru4xFwYOW8KE7dhn85I6hV4BGnnJEeRkkZTMElBL0JTNcFx0DzYDSc45Ni5EUfXS micUIgAIXZ+NwviGS1g71E7ulqNwpIRiDQ34bSfDVLd4icBE/5nr8itczOX2gcA3J/7/4/ tbOwHqHk8tL0kg9xme+deg8hLKdaI1AyRF4iSRBHsgujDywcpa+f1pnP+5JAslM+cwvyLt ZXfbCFBBTzDj1bNwRirmwJ2FWDsTi7zS1vEr7sLnfVfRcIG6nSbJxlTr88A+HWOcDFZUbK z2Jm1ho4d00Hd7vTVupf31vxdQAwii+4ihyl9ENueQ9ZK5fBjsWj7JlvovXVvA== Date: Fri, 26 Jul 2024 21:04:27 +0200 From: Kory Maincent To: Jacob Keller Cc: Florian Fainelli , Broadcom internal kernel review list , Andrew Lunn , Heiner Kallweit , Russell King , "David S. Miller" , "Eric Dumazet" , Jakub Kicinski , "Paolo Abeni" , Richard Cochran , "Radu Pirea" , Jay Vosburgh , Andy Gospodarek , Nicolas Ferre , Claudiu Beznea , Willem de Bruijn , Jonathan Corbet , Horatiu Vultur , , Simon Horman , "Vladimir Oltean" , , , , Thomas Petazzoni , , , , Maxime Chevallier , Rahul Rameshbabu , Willem de Bruijn , Shannon Nelson , Alexandra Winter Subject: Re: [PATCH net-next v17 12/14] net: ethtool: tsinfo: Add support for reading tsinfo for a specific hwtstamp provider Message-ID: <20240726210427.525c7abc@kmaincent-XPS-13-7390> In-Reply-To: <667b3700-e529-4d2e-9aa1-a738a1d70f0f@intel.com> References: <20240709-feature_ptp_netnext-v17-0-b5317f50df2a@bootlin.com> <20240709-feature_ptp_netnext-v17-12-b5317f50df2a@bootlin.com> <667b3700-e529-4d2e-9aa1-a738a1d70f0f@intel.com> Organization: bootlin X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-GND-Sasl: kory.maincent@bootlin.com Hello Jacob, Thanks a lot for your full review!=20 On Wed, 17 Jul 2024 10:35:20 -0700 Jacob Keller wrote: > On 7/9/2024 6:53 AM, Kory Maincent wrote: > [...] =20 >=20 > Reviewed-by: Jacob Keller >=20 > One thing which applies more broadly to the whole series, but I see the > focus right now is on selecting between NETDEV and PHYLIB. >=20 > For ice (E800 series) hardware, the timestamps are captured by the PHY, > but its not managed by phylib, its managed by firmware. In our case we > would obviously report NETDEV in this case. The hardware only has one > timestamp point and the fact that it happens at the PHY layer is not > relevant since you can't select or change it. >=20 > There are some future plans in the work for hardware based on the ixgbe > driver which could timestamp at either the MAC or PHY (with varying > trade-offs in precision vs what can be timestamped), and (perhaps > unfortunately), the PHY would likely not manageable by phylib. >=20 > There is also the possibility of something like DMA or completion > timestamps which are distinct from MAC timestamps. But again can have > varying trade offs. As we already discussed in older version of this patch series the hwtstamp qualifier will be used to select between IEEE 1588 timestamp or DMA timestamp. See patch 8 : +/* + * Possible type of htstamp provider. Mainly "precise" the default one + * is for IEEE 1588 quality and "approx" is for NICs DMA point. + */ We could add other enumeration values in the future if needed, to manage new cases. Just figured out there is a NIT in the doc. h*w*tstamp. > I'm hopeful this work can be extended somehow to enable selection > between the different mechanisms, even when the kernel device being > represented is the same netdev. Another nice features would be the support for simultaneous hardware timest= amp but I sadly won't be able to work on this. Regards, --=20 K=C3=B6ry Maincent, Bootlin Embedded Linux and kernel engineering https://bootlin.com