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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 86677C433E1 for ; Thu, 16 Jul 2020 05:46:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BFAA20760 for ; Thu, 16 Jul 2020 05:46:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594878388; bh=BmH10cHhH27muVWxBAjM/i7/M0wR1VcvJZxuw0jFn18=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Rus7EUlfWn2Qfp40AG75N0VpCY9txUVCPAJwYAsCH0saByfUZkTmTjDuT1yKffFiX KilO/0n49QDECg4E4YzKLD91p+Hhamhn8hu+dmI25B824HNtMwYUaUtBWTq0bwp8Ln MzX9W5piWCwfl6cL1vMs3nWiD9xrfhJSDuurr6xA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727105AbgGPFq2 (ORCPT ); Thu, 16 Jul 2020 01:46:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:39224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726696AbgGPFq1 (ORCPT ); Thu, 16 Jul 2020 01:46:27 -0400 Received: from localhost (unknown [122.171.202.192]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D77C320720; Thu, 16 Jul 2020 05:46:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594878386; bh=BmH10cHhH27muVWxBAjM/i7/M0wR1VcvJZxuw0jFn18=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zycc29BNsdTPucbeDp4pg2RnV9yK8wPrIsqi09c0bOwnIcrso8M05Zh2zy1vfIzgj ZRFBlVS1d4nYI6y3O3/5u12Ymr4snshoDpCYCLBc3LvWqFjYN4keFfHA1MYHS489Yz XWkvEvifJxWRODCFlsXJeq5WjozoY+0D+ydxjEk4= Date: Thu, 16 Jul 2020 11:16:22 +0530 From: Vinod Koul To: Russell King - ARM Linux admin Cc: Gregory CLEMENT , Andrew Lunn , Jason Cooper , devicetree@vger.kernel.org, Kishon Vijay Abraham I , Rob Herring , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth Subject: Re: [PATCH 2/2] phy: armada-38x: fix NETA lockup when repeatedly switching speeds Message-ID: <20200716054622.GD55478@vkoul-mobl> References: <20200630160452.GD1551@shell.armlinux.org.uk> <20200701065727.GY2599@vkoul-mobl> <20200710151921.GJ1551@shell.armlinux.org.uk> <20200713061846.GE34333@vkoul-mobl> <87365v5svd.fsf@FE-laptop> <20200713172140.GT1551@shell.armlinux.org.uk> <20200713180737.GU1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200713180737.GU1551@shell.armlinux.org.uk> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 13-07-20, 19:07, Russell King - ARM Linux admin wrote: > On Mon, Jul 13, 2020 at 06:21:40PM +0100, Russell King - ARM Linux admin wrote: > > On Mon, Jul 13, 2020 at 05:36:54PM +0200, Gregory CLEMENT wrote: > > > Hello, > > > > > > > On 10-07-20, 16:19, Russell King - ARM Linux admin wrote: > > > >> On Wed, Jul 01, 2020 at 12:27:27PM +0530, Vinod Koul wrote: > > > >> > On 30-06-20, 17:05, Russell King wrote: > > > >> > > The mvneta hardware appears to lock up in various random ways when > > > >> > > repeatedly switching speeds between 1G and 2.5G, which involves > > > >> > > reprogramming the COMPHY. It is not entirely clear why this happens, > > > >> > > but best guess is that reprogramming the COMPHY glitches mvneta clocks > > > >> > > causing the hardware to fail. It seems that rebooting resolves the > > > >> > > failure, but not down/up cycling the interface alone. > > > >> > > > > > >> > > Various other approaches have been tried, such as trying to cleanly > > > >> > > power down the COMPHY and then take it back through the power up > > > >> > > initialisation, but this does not seem to help. > > > >> > > > > > >> > > It was finally noticed that u-boot's last step when configuring a > > > >> > > COMPHY for "SGMII" mode was to poke at a register described as > > > >> > > "GBE_CONFIGURATION_REG", which is undocumented in any external > > > >> > > documentation. All that we have is the fact that u-boot sets a bit > > > >> > > corresponding to the "SGMII" lane at the end of COMPHY initialisation. > > > >> > > > > > >> > > Experimentation shows that if we clear this bit prior to changing the > > > >> > > speed, and then set it afterwards, mvneta does not suffer this problem > > > >> > > on the SolidRun Clearfog when switching speeds between 1G and 2.5G. > > > >> > > > > > >> > > This problem was found while script-testing phylink. > > > >> > > > > > >> > > Signed-off-by: Russell King > > > >> > > --- > > > >> > > arch/arm/boot/dts/armada-38x.dtsi | 3 +- > > > >> > > > > >> > lgtm, i need ack for dts parts before I can apply this > > > >> > > > >> I'm not sure what the situation is for Bootlin, but they don't seem to > > > >> be very responsive right now (covid related?) > > > >> > > > >> What I know from what I've been party to on netdev is that Bootlin > > > >> sent a patch for the MVPP2 driver, and the very next day someone > > > >> reported that the patch caused a bug. Unfortunately, the patch got > > > >> picked up anyway, but there was no response from Bootlin. After a > > > >> month or so, -final was released containing this patch, so now it > > > >> had become a regression - and still no response from Bootlin. > > > >> > > > >> Eventually the bug got fixed - not because Bootlin fixed it, but > > > >> because I ended up spending the time researching how that part of > > > >> the network driver worked, diagnosing what was going on, and > > > >> eventually fixing it in the most obvious way - but it's not clear > > > >> that the fix was the right approach. Bootlin never commented. See > > > >> 3138a07ce219 ("net: mvpp2: fix RX hashing for non-10G ports"). > > > >> > > > >> So, I think we have to assume that Bootlin are struggling right now, > > > >> and as it's been over a week, it's unlikely that they are going to > > > >> respond soon. What do you think we should do? > > > >> > > > >> I also note that Rob has not responded to the DT binding change > > > >> either, despite me gently prodding, and Rob processing a whole raft > > > >> of DT binding stuff yesterday. > > > >> > > > >> I can split the DTS change from the rest of the patch, but I don't > > > >> think that really helps without at least the binding change being > > > >> agreed. > > > > > > > > I would prefer splitting, you may sent the DTS to arm arch folks if no > > > > response from subarch folks > > > > > > Yes please could you split the patch to put the dts apart ? And if the > > > binding is accepted we will apply it. > > > > I don't see any sign that Rob will ever review the DTS part, so I'm > > at the point of just not caring about this anymore. I will carry it > > in my tree, but I'm going to do nothing further. > > > > That means that switching speed on mvneta on the Armada 38x is can > > cause the network to die, but hey, if people can't be bothered to > > review, and wish to impose rules such as "you can't change anything > > with DT without my express say so" which have the effect of blocking > > fixes, that's really not my problem. > > > > So, shrug, I'm giving up with these patches. Sorry. > > To be clear, this is not aimed at either Vinod or Gregory. Rob has acked, so if you can respin and split, I can apply -- ~Vinod