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 5D2B21D2B0F; Tue, 5 Nov 2024 10:20:20 +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=1730802023; cv=none; b=DwWfZfSAuN7nSTo5aIACEOjbbTnOt65AYzTjC+Fe4V4GnTUvBaPAEZzC5fGa/TyetCgCXH9hMpDFyWsUXCdETf71LY66JPqexspfzGV4ZisSyCiZJhIcgcMMoe+oRAy51gWWYNnmggVXabqoe9fkboBZo4um6baVxrzIgfOBrIQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730802023; c=relaxed/simple; bh=v3ndVqHP3JRvh4yNpNPFvc9eMbj704RDjLO3v5uk7+o=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=e26rrBfzB6B6HiQp28RWFiuk03P/dTcHZQmr+Fb+4t/doe1R81lafrOmn/dfEBnkQbHr62Y0o8KXfJ03X3jujXro66/x0hUa5cao8Yqq39AsvaBwW3RCCVbwE4cwrd3EigW6vGN5dlIXIFv/EU677muNfM5nd/uI8mrj41JpX08= 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=Yba7nZWr; 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="Yba7nZWr" Received: by mail.gandi.net (Postfix) with ESMTPSA id 3360540006; Tue, 5 Nov 2024 10:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1730802012; 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=frgUE9MhZvamkR8/ewj/FH/e6YcRGcG2QNQN+94jcNI=; b=Yba7nZWr2CAkTBIK7Mj2OKyXuhW8Vz19vTFCdmac8rpbineGSAFFAtemZixk7v1lofDUVW luBANgbVN0srjxsnSOZk7Q40+m6qUWTLnzyCTFhG9+TRKyP0isbXXDHCKq+4zN06GyCBK+ ukmpXaBubgFe/Gfuuns8mYFAiWNKxzisXVyZI7HbFavAJcVmM+B7/Kw+8tKXNJZEMW1lnP uXZ4O9NKC6LTV64+z3m7H6bBg7NVGUn9WqvOGe5M8lPlqJR1/ii2o9FJLjLETwoydNQXe5 icwpNbRbw7nQwZQSQBhp2raay6/zXxorSgG7rlAnLUq0dm/2j5gH+O5jTIrtYw== Date: Tue, 5 Nov 2024 11:20:10 +0100 From: Kory Maincent To: Oleksij Rempel Cc: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jonathan Corbet , Donald Hunter , Rob Herring , Andrew Lunn , Simon Horman , Heiner Kallweit , Russell King , Liam Girdwood , Mark Brown , Thomas Petazzoni , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, Kyle Swenson , Dent Project , kernel@pengutronix.de, Maxime Chevallier Subject: Re: [PATCH RFC net-next v2 15/18] net: pse-pd: Add support for getting and setting port priority Message-ID: <20241105112010.17d6f40b@kmaincent-XPS-13-7390> In-Reply-To: References: <20241030-feature_poe_port_prio-v2-0-9559622ee47a@bootlin.com> <20241030-feature_poe_port_prio-v2-15-9559622ee47a@bootlin.com> <20241031121104.6f7d669c@kmaincent-XPS-13-7390> 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 On Fri, 1 Nov 2024 11:23:06 +0100 Oleksij Rempel wrote: > On Fri, Nov 01, 2024 at 09:31:43AM +0100, Oleksij Rempel wrote: > > On Thu, Oct 31, 2024 at 12:11:04PM +0100, Kory Maincent wrote: =20 > > > On Thu, 31 Oct 2024 07:54:08 +0100 > > > Oleksij Rempel wrote: > > > =20 > [...] =20 > [...] =20 > > >=20 > > > Ack. So we assume PoDL could have the same interruption events. > > > =20 > [...] =20 > >=20 > > After thinking about it more overnight, I wanted to revisit the idea of > > having a priority strategy per port. Right now, if one port is set to > > static or dynamic mode, all disabled ports seem to have to follow it > > somehow too. This makes it feel like we should have a strategy for the > > whole power domain, not just for each port. > >=20 > > I'm having trouble imagining how a per-port priority strategy would wor= k in > > this setup. Indeed you are right. I was first thinking of using the same port priority = for all the ports of a PSE but it seems indeed better to have it by Power domai= n. > > Another point that came to mind is that we might have two different > > components here, and we need to keep these two parts separate in follow= -up > > discussions: > >=20 > > - **Budget Evaluation Strategy**: The static approach seems > > straightforward=E2=80=94if a class requests more than available, approp= riate > > actions are taken. However, the dynamic approach has more complexity, s= uch > > as determining the threshold, how long violations can be tolerated, and > > whether a safety margin should be maintained before exceeding maximum l= oad. > >=20 > > - **Disconnection Policy**: Once a budget violation is detected, this > > decides how to react, like which ports should be disconnected and in wh= at > > order. > >=20 > > Would it make more sense to have a unified strategy for power domains, > > where we apply the same budget evaluation mode (static or dynamic) and > > disconnection policy to all ports in that domain? This could make the > > configuration simpler and the power management more predictable. =20 Yes, these policies and the port priority mode should be per power domains.= =20 > Except of user reports, do we have documented confirmation about dynamic > Budget Evaluation Strategy in PD692x0 firmware? >=20 > Do this configuration bits are what I called Budget Evaluation Strategy? > Version 3.55: > Bits [3..0]=E2=80=94BT port PM mode > 0x0: The port power that is used for power management purposes is > dynamic (Iport x Vmain). Yes it seems so. I can't find any more configurations on the budget evaluat= ion strategy than the power limit. Regards, --=20 K=C3=B6ry Maincent, Bootlin Embedded Linux and kernel engineering https://bootlin.com