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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 E9D94C433EF for ; Tue, 21 Sep 2021 02:37:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEAE161157 for ; Tue, 21 Sep 2021 02:37:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350775AbhIUCij (ORCPT ); Mon, 20 Sep 2021 22:38:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349303AbhIUCZr (ORCPT ); Mon, 20 Sep 2021 22:25:47 -0400 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE493C0A88DE for ; Mon, 20 Sep 2021 11:58:59 -0700 (PDT) Received: by mail-ed1-x534.google.com with SMTP id eg28so42500855edb.1 for ; Mon, 20 Sep 2021 11:58:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=6exHgK6vGzAOEpe1ocoQSvp6Lvs/E+5qV0A++5q/Iqk=; b=Cx782PC/TMmkVC0GOVBe5SmMzh2krQUt91kXVnGtUd4tc4FGsSR8j8jMP/WKThKE2l PSyis9Qd5sgbA6Fwk6cdc90Dikgp8aHCjgl/dvD4HQNEgjDnbcMTh1aAsZ5pZH1y1Cg2 byrcj9C2D6BkOMpnMTL/lCXTqE4GHlrzbNRlII26nO6Uwjl4IsRrG/WNvhsPg2AM08H/ iYJIjWWW1jaHSOm0vRqeyYGWtezLqgMgKRzBpH1ZCFPELku+NCHGw4IZfe4hLiv4Et0w jFufukAkUnXb6gxiDxG6GlD7oLVpFh8aOU6vfb4vlxeTAEkSXQtjmxFhYpJxIjAybxLm u39A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=6exHgK6vGzAOEpe1ocoQSvp6Lvs/E+5qV0A++5q/Iqk=; b=0AqYZ4lxs1qc2ZFYN50jI7gR/wIMEoUydsG9//Yc7ocnFGpJTNQYq9jCly71t4iVS3 Mp7nq2w9ymEJvqJlPPDqBAF/03S9c5NBgQSTPBomjHsxqqC5t+3SfU/fXb3+eFfaKzhG vUEHyBy4D3EvQa9mQckmnvZ9+RcFcCA4w5U2GxfKayllBTIcXkZv21qTNV4+GcTOPqFX gvLRISVi2eGPRKkHasgSA8DVN/cRp5CrjfmB4xMpbPrNI1TnNMQN0z/Q9yiR/iYbU16y mNBMGGj8V5XIQDL9kuhYLAXAr7eG4pWU3glhSl79Egj0QWPYbjYdNvZ1JWEkXjQogpWR pa6Q== X-Gm-Message-State: AOAM533kTmBhg0d3IRQhaGLE3XHzun1bjUlnZmIBeyKJoHK44wckbR+B BIsc9INFZ0Fbot5L0bOxT04= X-Google-Smtp-Source: ABdhPJyCaYQMrC4jUgnsT3g0zODNYmLSd6K4OdsBQvUhjrXO6PYbJ7eJ4mN/Bzlz+Ugms427Wxr0EQ== X-Received: by 2002:a17:906:c1d0:: with SMTP id bw16mr31062856ejb.146.1632164338426; Mon, 20 Sep 2021 11:58:58 -0700 (PDT) Received: from skbuf ([82.78.148.104]) by smtp.gmail.com with ESMTPSA id w13sm7894882ede.24.2021.09.20.11.58.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Sep 2021 11:58:57 -0700 (PDT) Date: Mon, 20 Sep 2021 21:58:56 +0300 From: Vladimir Oltean To: Florian Fainelli Cc: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , Network Development , Andrew Lunn , Heiner Kallweit , Russell King Subject: Re: Race between "Generic PHY" and "bcm53xx" drivers after -EPROBE_DEFER Message-ID: <20210920185856.4mffcj7rifslxyil@skbuf> References: <3639116e-9292-03ca-b9d9-d741118a4541@gmail.com> <4648f65c-4d38-dbe9-a902-783e6dfb9cbd@gmail.com> <20210920170348.o7u66gpwnh7bczu2@skbuf> <11994990-11f2-8701-f0a4-25cb35393595@gmail.com> <20210920174022.uc42krhj2on3afud@skbuf> <25e4d46a-5aaf-1d69-162c-2746559b4487@gmail.com> <20210920180240.tyi6v3e647rx7dkm@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Sep 20, 2021 at 11:10:39AM -0700, Florian Fainelli wrote: > > But even so, what's a "pseudo PHY" exactly? I think that's at the bottom > > of this issue. In the Linux device model, a device has a single driver. > > In this case, the same MDIO device either has a switch driver, if you > > accept it's a switch, or a PHY driver, if you accept it's a PHY. > > I said it's "broken" because the expectation seems to be that it's a switch, > > but it looks like it's treated otherwise. Simply put, the same device > > can't be both a switch and a PHY. > > A pseudo-PHY is a device that can snoop and respond to MDIO bus > requests. I understand it cannot be both, just explaining to you how the > people at Broadcom have been seeing the world from their perspective. > Anything that is found at MDIO address 0x1e/30 is considered a MDIO > attached switch, that's all. Nothing wrong with that per se, at NXP we've been thinking about RevMII as well, and having a switch expose itself as a PHY over MDIO, in any case something a bit richer/more interactive than a fixed-link. One way to bypass that limitation is to access the switch registers through a different device compared to the PHY device. At the very least, a different MDIO address. Even better, not over MDIO at all, but something faster, SPI, PCIe etc.