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 AACA4C46467 for ; Wed, 11 Jan 2023 13:08:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231845AbjAKNHz (ORCPT ); Wed, 11 Jan 2023 08:07:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229737AbjAKNHw (ORCPT ); Wed, 11 Jan 2023 08:07:52 -0500 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DE1921A; Wed, 11 Jan 2023 05:07:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=UXiBWiMARtUARLuVCb/C2RAQABw9gUr7NLniBV1MKfk=; b=v9Jqcagt5k7zvlgVRWSVVLCYJ9 hMkvfw1OzI8T39q5Dat2q4A27PoXAQk+IbDHCGNspW80gZSS9jFNPfWnzvk9LRXPUjeB55cDeMhUY yjp3auB60Y3lJytugTAXmY1sEHuzlQBAfubNMJqFruBNcWp6bYWCTL6jY50SN/VO4jD4=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1pFapH-001mEh-DM; Wed, 11 Jan 2023 14:07:31 +0100 Date: Wed, 11 Jan 2023 14:07:31 +0100 From: Andrew Lunn To: "Frank.Sae" Cc: Peter Geis , Heiner Kallweit , Russell King , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , xiaogang.fan@motor-comm.com, fei.zhang@motor-comm.com, hua.sun@motor-comm.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH net-next v1 1/3] dt-bindings: net: Add Motorcomm yt8xxx ethernet phy Driver bindings Message-ID: References: <20230105073024.8390-1-Frank.Sae@motor-comm.com> <20230105073024.8390-2-Frank.Sae@motor-comm.com> <83fd7a69-7e6a-ab93-b05a-4eba8af4d245@motor-comm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <83fd7a69-7e6a-ab93-b05a-4eba8af4d245@motor-comm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > RX delay = rx-delay-basic (0ns or 1.9ns) + x-delay-additional-ps > (N*150ps, N = 0 ~ 15) > If rx-delay-basic is removed and controlled by phy-mode. > when phy-mode is rgmii-id or rgmii-rxid, RX delay is 1.9ns + N*150ps. > But sometimes 1.9ns is still too big, we just need 0ns + N*150ps. > > For this case, can we do like following ? > rx-internal-delay-ps: > enum: [ 0, 150, 300, 450, 600, 750, 900, 1050, 1200, 1350, 1500, > 1650, 1800, 1900, 1950, 2050, 2100, 2200, 2250, 2350, 2500, 2650, 2800, > 2950, 3100, 3250, 3400, 3550, 3700, 3850, 4000, 4150 ] > default: 0 > rx-internal-delay-ps is 0ns + N*150ps and 1.9ns + N*150ps. > And check whether need rx-delay-basic (1.9ns) by the val of > rx-internal-delay-ps? Nothing says delays are only positive. So you could have rgmii-id or rgmii-rxid and a rx-internal-delay-ps of -150, if you need less than 1.9ns. As i said, rx-internal-delay-ps is used to fine tune the delay. > We can't reduce this down to tx-clk-inverted. > There are two mac and two yt8531 on their board. Each of yt8531 need > different config in DTS. They need adjust tx clk delay in > link_change_notify callback function according to current speed. > > They configured tx-clk-xxxx-inverted like this : > > speed GMAC0 GMAC1 > 1000M 1 0 tx-clk-1000-inverted > 100M 1 1 tx-clk-100-inverted > 10M 0/1 0/1 tx-clk-10-inverted What MAC is this? It seems very oddly designed, getting close to broken. I've not seen any other MAC/PHY combination need anything like this. > Can we put tx-clk-adj-enabled, tx-clk-10-inverted, tx-clk-100-inverted > and tx-clk-1000-inverted in tx-clk-10-inverted like bit in byte? No, they are individual boolean properties, so should be kept as they are. But i really think somebody should be looking deep into the MAC design to understand why it is like this, and if the MAC can sort out this mess itself. Andrew