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 8291EC63797 for ; Tue, 17 Jan 2023 13:30:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230282AbjAQNaa (ORCPT ); Tue, 17 Jan 2023 08:30:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229730AbjAQNa2 (ORCPT ); Tue, 17 Jan 2023 08:30:28 -0500 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E822538EA5 for ; Tue, 17 Jan 2023 05:30:27 -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=1wIVZSVUgTUedV2LQo9/FHDRbS3j1hP9CCyFacP4Lu0=; b=mZQbWh0YsZcChCYJOyOVHzBOmN QV1tP2wkYK8wpRRzlXwWKJMTwxlRLSyR3Hn4PpnwpEhU5Jb9Lw/yGDwq63BG+UQFbGmuo80vOvC60 Ny3PIdAfGTFx6mMFT794GGZYqTvGf858VSB/B2zTp4PWOorGQegTqPp9lx3t9k4JJAvQ=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1pHm2d-002KAi-AQ; Tue, 17 Jan 2023 14:30:19 +0100 Date: Tue, 17 Jan 2023 14:30:19 +0100 From: Andrew Lunn To: Paolo Abeni Cc: Heiner Kallweit , Neil Armstrong , Russell King - ARM Linux , David Miller , Eric Dumazet , Jakub Kicinski , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , "netdev@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "open list:ARM/Amlogic Meson..." Subject: Re: [PATCH net-next] net: phy: meson-gxl: support more G12A-internal PHY versions Message-ID: References: <03ea260e-f03c-d9d7-6f5f-ff72836f5739@gmail.com> <51abd8ca-8172-edfa-1c18-b1e48231f316@linaro.org> <6de25c61-c187-fb88-5bd7-477b1db1510e@gmail.com> <699f6ee109b3a72b2b377f42a78705f47d4a77b9.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <699f6ee109b3a72b2b377f42a78705f47d4a77b9.camel@redhat.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > > The PHY compatible string in DT is the following in all cases: > > compatible = "ethernet-phy-id0180.3301" This form of compatible has two purposes. 1) You cannot read the PHY ID register during MDIO bus enumeration, generally because you need to turn on GPIOs, clocks, regulators etc, which the MDIO/PHY core does not know how to do. 2) The PHY has bad values in its ID registers, typically because the manufactures messed up. If you have a compatible like this, the ID registers are totally ignored by Linux, and the ID is used to find the driver and tell the driver exactly which of the multiple devices it supports it should assume the device is. So you should use this from of compatible with care. You can easily end up thinking you have a different PHY to what you actually have, which could then result in wrong erratas being applied etc, or even the wrong driver being used. Andrew