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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E8BEC5479D for ; Fri, 6 Jan 2023 23:29:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229586AbjAFX3O (ORCPT ); Fri, 6 Jan 2023 18:29:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231375AbjAFX3K (ORCPT ); Fri, 6 Jan 2023 18:29:10 -0500 Received: from mail-ed1-x52b.google.com (mail-ed1-x52b.google.com [IPv6:2a00:1450:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3466488DF0; Fri, 6 Jan 2023 15:29:09 -0800 (PST) Received: by mail-ed1-x52b.google.com with SMTP id v10so3069530edi.8; Fri, 06 Jan 2023 15:29:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=V/CHtBfuoBwh3965bbOqa0bDVHTb0f8Tm9+/rTtd0Ow=; b=nNAFW27qekariEEjM4E0cydMN3kbkhn3rQ/aRH9h+cCh0JvnkXT2jOk5cukqT1gDGi v3AsbnQIGDzbKRHZSTrQwI7qVOYhHt7fXeaQK31dgtRcbCy98nCiO+ZoCI2o1k1IiDFu ao9r5KKjtgKBjtuKzsXll+FMEYr7QtmyEEWaK+uoOWSkzqVf1/LXrwYmq+260iv203W/ YbV+6cFzM00ABf1Mf9dyzNMN3tZmxi79HUvJRcK67ruEbW0hCPYeJz966mWsjMGNoBU+ bonmGWw16jiZpsbAEKELucLVMwWFhVJUUrLTT2uePgbllnFcOBm3jMQDg7K8qEKsUlwz s9Bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=V/CHtBfuoBwh3965bbOqa0bDVHTb0f8Tm9+/rTtd0Ow=; b=NmpWPsdJXE9dATdPQmdkZ22hoqCJG/c9VndUHzZuRLV/vwghATlj5WPDp4NUnmgWEd 7n+B65udy94JM0hSTh2VoojjHNZEgcTTbE/ddaNddOtDPe71tWPPSNCdvU24Q+qaHS8r 9zcZWJs/p4EwYYpKZa9WXdJZFmll/vJiR2D16uLKwTTedjRjeY/EAufUh11SW20l30fH BUWixtFa0jg13bKxNCZFovoHafm5N8hXMk2+fqHksk0s4+MSGL04mxHGoYk8vQxZYy09 WL7vqjvCk9MEorbMeevuwy3IEEbl8+mGkUhNcGQutuDlA2f2D6y2MTf4zYZU29lRz89k vSHw== X-Gm-Message-State: AFqh2ko4QyHdTky3Ty+3CwXtRPhj7u+LbMnFlbG7ig7RfV4RR3Ud3nSa awPWtUBMU8n1b1ILlJ3idpQ= X-Google-Smtp-Source: AMrXdXsn0WEffBN4eL5PkzFeQq844b6d6Xzq6XU0xN5TrtgLG+1qyX57k8ID7qYKnH0Sw33cc1fZnA== X-Received: by 2002:aa7:d789:0:b0:497:4f53:ee8f with SMTP id s9-20020aa7d789000000b004974f53ee8fmr2427276edq.39.1673047747602; Fri, 06 Jan 2023 15:29:07 -0800 (PST) Received: from skbuf ([188.26.184.223]) by smtp.gmail.com with ESMTPSA id p18-20020a50cd92000000b0046ba536ce52sm925379edi.95.2023.01.06.15.29.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Jan 2023 15:29:07 -0800 (PST) Date: Sat, 7 Jan 2023 01:29:05 +0200 From: Vladimir Oltean To: Sean Anderson Cc: "Russell King (Oracle)" , Andrew Lunn , Heiner Kallweit , netdev@vger.kernel.org, "David S . Miller" , Paolo Abeni , linux-kernel@vger.kernel.org, Jakub Kicinski , Eric Dumazet , Tim Harvey Subject: Re: [PATCH net-next v5 4/4] phy: aquantia: Determine rate adaptation support from registers Message-ID: <20230106232905.ievmjro2asx3dv3s@skbuf> References: <20230103220511.3378316-1-sean.anderson@seco.com> <20230103220511.3378316-5-sean.anderson@seco.com> <20230105140421.bqd2aed6du5mtxn4@skbuf> <6ffe6719-648c-36aa-74be-467c8db40531@seco.com> <20230105173445.72rvdt4etvteageq@skbuf> <20230106230343.2noq2hxr4quqbtk4@skbuf> <3ede0be8-4da5-4f64-6c67-4c9e7853ea50@seco.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ede0be8-4da5-4f64-6c67-4c9e7853ea50@seco.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 06, 2023 at 06:21:26PM -0500, Sean Anderson wrote: > On 1/6/23 18:03, Vladimir Oltean wrote: > > On Thu, Jan 05, 2023 at 05:46:48PM +0000, Russell King (Oracle) wrote: > >> On Thu, Jan 05, 2023 at 07:34:45PM +0200, Vladimir Oltean wrote: > >> > So we lose the advertisement of 5G and 2.5G, even if the firmware is > >> > provisioned for them via 10GBASE-R rate adaptation, right? Because when > >> > asked "What kind of rate matching is supported for 10GBASE-R?", the > >> > Aquantia driver will respond "None". > >> > >> The code doesn't have the ability to do any better right now - since > >> we don't know what sets of interface modes _could_ be used by the PHY > >> and whether each interface mode may result in rate adaption. > >> > >> To achieve that would mean reworking yet again all the phylink > >> validation from scratch, and probably reworking phylib and most of > >> the PHY drivers too so that they provide a lot more information > >> about their host interface behaviour. > >> > >> I don't think there is an easy way to have a "perfect" solution > >> immediately - it's going to take a while to evolve - and probably > >> painfully evolve due to the slowness involved in updating all the > >> drivers that make use of phylink in some way. > > > > Serious question. What do we gain in practical terms with this patch set > > applied? With certain firmware provisioning, some unsupported link modes > > won't be advertised anymore. But also, with other firmware, some supported > > link modes won't be advertised anymore. > > Well, before the rate adaptation series, none of this would be > advertised. I would rather add advertisement only for what we can > actually support. We can always come back later and add additional > support. Well, yes. But practically, does it matter that we are negotiating a link speed that we don't support, when the effect is the same (link doesn't come up)? The only practical case I see is where advertising e.g. an unsupported 2.5G would cause the link to not establish at a supported 1G. But as you say, I don't think this will be the case with the firmware provisioning that Tim gave as an example? > > IIUC, Tim Harvey's firmware ultimately had incorrect provisioning, it's > > not like the existing code prevents his use case from working. > > The existing code isn't great as-is, since all the user sees is that we > e.g. negotiated for 1G, but the link never came up. > > --Sean