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=-8.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 CC2D8C433F2 for ; Fri, 10 Jul 2020 15:20:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A28782065D for ; Fri, 10 Jul 2020 15:20:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="htsOdPA0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728047AbgGJPUQ (ORCPT ); Fri, 10 Jul 2020 11:20:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726920AbgGJPTj (ORCPT ); Fri, 10 Jul 2020 11:19:39 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 238CBC08C5DC for ; Fri, 10 Jul 2020 08:19:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=m2mF24K7LscLtR40pVBv3aocC9vyfFMSah5juMJyYWs=; b=htsOdPA0UdU7nVoHiDj140Rea fAkzwaBhqOGbRH0Y5FGSAXOQMxXmJZfMZfpd3AUB8JGD+2YQx4xksgLzNFXsfmKEk6LPLLaMZ/Ein lh9a7XqJS7JHNLGsUMo6F4A9Wx9tUnHXtlDEjxFmASgAPKckIxPfCZVJO2yfMGvr0ZbX7MjEFs/2I Q6IgSCbyr74LWiHxBvUNAZzkF1tsoWFeTPbhfwKr9A/PfJ6LZ4jLgHiq7J1S1gjCOpTFPlpwYIQrO jWHxGZkWSpFnOE7HANRuc4I5745nM7EMbumquD/z47DGNJlnONuFO8Bk+62wZm6N/f4PtCU6TEOC4 n5uxcc+Mg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:37766) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jtuo6-0001px-Qr; Fri, 10 Jul 2020 16:19:22 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jtuo5-0003Ll-OY; Fri, 10 Jul 2020 16:19:21 +0100 Date: Fri, 10 Jul 2020 16:19:21 +0100 From: Russell King - ARM Linux admin To: Vinod Koul Cc: Andrew Lunn , Gregory Clement , Jason Cooper , Kishon Vijay Abraham I , Rob Herring , Sebastian Hesselbarth , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/2] phy: armada-38x: fix NETA lockup when repeatedly switching speeds Message-ID: <20200710151921.GJ1551@shell.armlinux.org.uk> References: <20200630160452.GD1551@shell.armlinux.org.uk> <20200701065727.GY2599@vkoul-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200701065727.GY2599@vkoul-mobl> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!