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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 C9BDDC433DB for ; Thu, 21 Jan 2021 00:57:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7968323888 for ; Thu, 21 Jan 2021 00:57:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732465AbhAUA5a (ORCPT ); Wed, 20 Jan 2021 19:57:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:58290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730588AbhAUAR2 (ORCPT ); Wed, 20 Jan 2021 19:17:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DAC122360D; Thu, 21 Jan 2021 00:16:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611188199; bh=oSY5j1RwH+0tuI91BJXdScP9I35wwPguytRpawcS3Hg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=foiLhMPztwwV3SbKC2/I0tpE4Q3XWNw6Y4M1i+GguJIWrP4Ur7UrZmhFchJ4MqmGd lDA9l1FHxde3rmL4yVSXcnOCKPh/lGWID3WK2I7I5rjkVdqSI/4kDaewKfxWZ8KXjO 4zVpVbQIsg49UFB1PRNcT5aPePfATZRMkW5vArqm2NOY9kmQ+KUSRpf9+Ybb+VXP8F Ap//ZeLSiF7fOPhCMgmCHNfXOxuHJPk3fembMCJ+Gpx9ZOBjgm2RtNS9Qu8ucPmBrq Jzi/p4mod1D+CUArtKtiTP3txE7rn2jiU9EAolRF8JpOiI/OlHXWIf0zf2aGFW0z/G F1cArgzR0/5nQ== Date: Wed, 20 Jan 2021 16:16:37 -0800 From: Jakub Kicinski To: Andrew Lunn Cc: Jiri Pirko , netdev@vger.kernel.org, davem@davemloft.net, jacob.e.keller@intel.com, roopa@nvidia.com, mlxsw@nvidia.com Subject: Re: [patch net-next RFC 00/10] introduce line card support for modular switch Message-ID: <20210120161637.6735ef4a@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: References: <20210113121222.733517-1-jiri@resnulli.us> <20210119115610.GZ3565223@nanopsycho.orion> <20210120083605.GB3565223@nanopsycho.orion> <20210120154158.206b8752@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 21 Jan 2021 01:01:21 +0100 Andrew Lunn wrote: > On Wed, Jan 20, 2021 at 03:41:58PM -0800, Jakub Kicinski wrote: > > On Wed, 20 Jan 2021 14:56:46 +0100 Andrew Lunn wrote: =20 > > > > No, the FW does not know. The ASIC is not physically able to get the > > > > linecard type. Yes, it is odd, I agree. The linecard type is known = to > > > > the driver which operates on i2c. This driver takes care of power > > > > management of the linecard, among other tasks. =20 > > >=20 > > > So what does activated actually mean for your hardware? It seems to > > > mean something like: Some random card has been plugged in, we have no > > > idea what, but it has power, and we have enabled the MACs as > > > provisioned, which if you are lucky might match the hardware? > > >=20 > > > The foundations of this feature seems dubious. =20 > >=20 > > But Jiri also says "The linecard type is known to the driver which > > operates on i2c." which sounds like there is some i2c driver (in user > > space?) which talks to the card and _does_ have the info? Maybe I'm > > misreading it. What's the i2c driver? =20 >=20 > Hi Jakub >=20 > A complete guess, but i think it will be the BMC, not the ASIC. There > have been patches from Mellanox in the past for a BMC, i think sent to > arm-soc, for the ASPEED devices often used as BMCs. And the BMC is > often the device doing power management. So what might be missing is > an interface between the driver and the BMC. But that then makes the > driver system specific. A OEM who buys ASICs and makes their own board > could have their own BMC running there own BMC firmware. >=20 > All speculation... I see that does make sense =F0=9F=A4=94=20