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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 848FAC433E0 for ; Wed, 17 Jun 2020 11:57:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6296420CC7 for ; Wed, 17 Jun 2020 11:57:51 +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="SZ20Css2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726727AbgFQL5t (ORCPT ); Wed, 17 Jun 2020 07:57:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726280AbgFQL5q (ORCPT ); Wed, 17 Jun 2020 07:57:46 -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 11945C061573 for ; Wed, 17 Jun 2020 04:57:46 -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=XzAEQto/Af7+9WmajIFHZYz09OvioF7M8FcNyEuPJRQ=; b=SZ20Css2hTFhzfxCsMQev4cWF 9KTaFgGVr4COvknkeXFQdi/f3GqVAJnKUH0QQtphloiGKCojBWx9DXlyr8b6pWGD7VRWat062baFB jgVh998MXepCOJ6oCZHjS3HJYhEc3VPGYo2IQSOUbSM2oUJTYDzBsDoJrBOARZD4gX2ICPb7PWiV9 ZUwANhzuJNZha9wzeT1kn1yQE3g9lgoO7n5ZSxAFRsspHLlN8R0b2J8WvqvvFOX9udANUbRuJa27r SBI+7Asfonfqfs/QcDfxGvO87vRR4UsNk3S3d6S36QyG0WxikkGyJ60N+/XEJL8fZ+q8EUMN/qTMa sib7NH1tw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:58466) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jlWhC-0003ic-J4; Wed, 17 Jun 2020 12:57:34 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jlWh4-0003i0-1k; Wed, 17 Jun 2020 12:57:26 +0100 Date: Wed, 17 Jun 2020 12:57:26 +0100 From: Russell King - ARM Linux admin To: Vladimir Oltean Cc: Helmut Grohne , Nicolas Ferre , "David S. Miller" , Jakub Kicinski , Palmer Dabbelt , Paul Walmsley , netdev Subject: Re: [PATCH] net: macb: reject unsupported rgmii delays Message-ID: <20200617115725.GR1551@shell.armlinux.org.uk> References: <20200616074955.GA9092@laureti-dev> <20200617105518.GO1551@shell.armlinux.org.uk> <20200617113410.GP1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Jun 17, 2020 at 02:38:25PM +0300, Vladimir Oltean wrote: > On Wed, 17 Jun 2020 at 14:34, Russell King - ARM Linux admin > wrote: > > > > > > > Why are you so abrasive? > > > > Not responding to this until you start behaving more reasonably. > > > > -- > > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > > FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! > > Sorry. > What I meant to say is: the documentation is unclear. It has been > interpreted in conflicting ways, where the strict interpretations have > proven to have practical limitations, and the practical > interpretations have been accused of being incorrect. In my opinion > there is no way to fix it without introducing new bindings, which I am > not sure is really worth doing. The documentation was added in 2016, many years after we have had users of this, in an attempt to clear up some of the confusion. It is likely that it had to cater for existing users though - I'm sure if Florian cares, he can comment on that. It would be better if it made a definitive statement about it, but doing so would likely attract pedants to try to fix everything to conform, causing breakage in the process. I've recently had a painful experience of this with the Atheros PHYs, where there are lots of platforms using "rgmii" when they should have been using "rgmii-id". A patch changed this in the Atheros code breaking all these platforms, breakage which persisted over several kernel versions, needing fixes to DT files that then had to be back-ported. That's fine if you know what happened to break it, but if you don't, and you don't know what the fix is, you're mostly stuffed and stuck with non- working ethernet. That really was not nice. This is one of the reasons why I press for any new PHY interface mode to be documented in the phylib documentation right from the start, so that hopefully we can avoid this kind of thing in the future. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!