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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05BE9C4338F for ; Thu, 19 Aug 2021 07:50:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D414760560 for ; Thu, 19 Aug 2021 07:50:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234640AbhHSHvW (ORCPT ); Thu, 19 Aug 2021 03:51:22 -0400 Received: from new3-smtp.messagingengine.com ([66.111.4.229]:45983 "EHLO new3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229927AbhHSHvV (ORCPT ); Thu, 19 Aug 2021 03:51:21 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailnew.nyi.internal (Postfix) with ESMTP id 12EEA580CB1; Thu, 19 Aug 2021 03:50:45 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Thu, 19 Aug 2021 03:50:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=9ZqtJn J0H+EdolVALfJ0fnZU/c0Rk6VytaazMf6oyuk=; b=lDS8qoC7R4OglpoH7ph+N2 NntI/nnJyXQ/t/Y3LOQ3b8t7skehEIFGn4AbBHxjaD2u5D39aXxRshWfAiZDVihn 37FVNt9XUaHPI7bfaQ4zCY9sBHuhdHmVR+vLCwWzdV7DTFpO3iNKorPHPXQh2YAl oAkZ6eG6DQ4icZBsEM8wIRnJihB2mhutTqqPelE0HOKgLcRRysIpLgUvOh8EDk/C CuTHtMygO0YY0UIA7u7BfPuaKH5rao8R+IzPsjOn3vVZ8534tSQ6F884oTwRNJpa r+3j0p9Jj18shjxswwVSr3UbE4rGTitG5KKzp7AuZfI3dJkr7ppWl1345kiNbQpA == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrleeigdduvdefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefkughoucfu tghhihhmmhgvlhcuoehiughoshgthhesihguohhstghhrdhorhhgqeenucggtffrrghtth gvrhhnpedtffekkeefudffveegueejffejhfetgfeuuefgvedtieehudeuueekhfduheel teenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehiug hoshgthhesihguohhstghhrdhorhhg X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 19 Aug 2021 03:50:42 -0400 (EDT) Date: Thu, 19 Aug 2021 10:50:39 +0300 From: Ido Schimmel To: Andrew Lunn Cc: Jakub Kicinski , netdev@vger.kernel.org, davem@davemloft.net, mkubecek@suse.cz, pali@kernel.org, jacob.e.keller@intel.com, jiri@nvidia.com, vadimp@nvidia.com, mlxsw@nvidia.com, Ido Schimmel Subject: Re: [RFC PATCH net-next v2 1/6] ethtool: Add ability to control transceiver modules' power mode Message-ID: References: <20210818155202.1278177-1-idosch@idosch.org> <20210818155202.1278177-2-idosch@idosch.org> <20210818153241.7438e611@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.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: netdev@vger.kernel.org On Thu, Aug 19, 2021 at 12:55:43AM +0200, Andrew Lunn wrote: > On Wed, Aug 18, 2021 at 03:32:41PM -0700, Jakub Kicinski wrote: > > On Wed, 18 Aug 2021 18:51:57 +0300 Ido Schimmel wrote: > > > +MODULE_SET > > > +========== > > > + > > > +Sets transceiver module parameters. > > > + > > > +Request contents: > > > + > > > + ====================================== ====== ========================== > > > + ``ETHTOOL_A_MODULE_HEADER`` nested request header > > > + ``ETHTOOL_A_MODULE_POWER_MODE_POLICY`` u8 power mode policy > > > + ====================================== ====== ========================== > > > + > > > +When set, the optional ``ETHTOOL_A_MODULE_POWER_MODE_POLICY`` attribute is used > > > +to set the transceiver module power policy enforced by the host. Possible > > > +values are: > > > + > > > +.. kernel-doc:: include/uapi/linux/ethtool.h > > > + :identifiers: ethtool_module_power_mode_policy > > > + > > > +For SFF-8636 modules, low power mode is forced by the host according to table > > > +6-10 in revision 2.10a of the specification. > > > + > > > +For CMIS modules, low power mode is forced by the host according to table 6-12 > > > +in revision 5.0 of the specification. > > > + > > > +To avoid changes to the operational state of the device, power mode policy can > > > +only be set when the device is administratively down. > > > > Would you mind explaining why? > > Part of the issue is we have two different sorts of policy mixed > together. > > ETHTOOL_MODULE_POWER_MODE_POLICY_LOW and > ETHTOOL_MODULE_POWER_MODE_POLICY_HIGH change the state now. This could > be a surprise to a user when there link disappears for the > ETHTOOL_MODULE_POWER_MODE_POLICY_LOW case, when the interface is admin up. > > ETHTOOL_MODULE_POWER_MODE_POLICY_HIGH_ON_UP however follows the state > of the interface. So there should not be any surprises. > > I actually think ETHTOOL_MODULE_POWER_MODE_POLICY_HIGH_ON_UP should be > allowed at any time, just to make it easier to use. Yes > > > > +/** > > > + * enum ethtool_module_power_mode_policy - plug-in module power mode policy > > > + * @ETHTOOL_MODULE_POWER_MODE_POLICY_LOW: Module is always in low power mode. > > > > Did you have a use case for this one or is it for completeness? Seems > > like user can just bring the port down if they want no carrier? My > > understanding was you primarily wanted the latter two, and those can > > be freely changed when netdev is running, right? > > > > > + * @ETHTOOL_MODULE_POWER_MODE_POLICY_HIGH: Module is always in high power mode. > > > + * @ETHTOOL_MODULE_POWER_MODE_POLICY_HIGH_ON_UP: Module is transitioned by the > > > + * host to high power mode when the first port using it is put > > > + * administratively up and to low power mode when the last port using it > > > + * is put administratively down. > > > > s/HIGH_ON_UP/AUTO/ ? > > high on up == low on down, right, seems arbitrary to pick one over the > > other > > Should we also document what the default is? Seems like > ETHTOOL_MODULE_POWER_MODE_POLICY_HIGH_ON_UP is the generic network > interface default, so maybe it should also be the default for SFPs? I will add a note in Documentation/networking/ethtool-netlink.rst that the default power mode policy is driver-dependent (can be queried) and that it can either be 'high' or 'auto'. > > Andrew