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 54EAFC433EF for ; Mon, 20 Sep 2021 18:49:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D79F61211 for ; Mon, 20 Sep 2021 18:49:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354119AbhITSu4 (ORCPT ); Mon, 20 Sep 2021 14:50:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383927AbhITSqP (ORCPT ); Mon, 20 Sep 2021 14:46:15 -0400 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D925FC09CE7C for ; Mon, 20 Sep 2021 10:03:58 -0700 (PDT) Received: by mail-ed1-x532.google.com with SMTP id v5so62786615edc.2 for ; Mon, 20 Sep 2021 10:03:58 -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:content-transfer-encoding:in-reply-to; bh=KY3/Fe4BV/74ZiMw1TvpKdEkm/AsQHzqLHKHNu/kDmc=; b=Q/Ys7GbWWpuVI440i0JAGFeXPPptOYdYQVtpkoS49tv/tpV8zttW7xqsOyfk4y/ck6 wByxL1fmsIgOwPBY8GXugOwNtQKkDUqqydQBskl1ncd3HPNND+0Stg9EZlzAF/47jKVB ds8c73TglWaS7jR9IS9Typa+kRbOczPrPqlAKayNuKW2XlmKiOIM9K7rWuoYYiisW+CV AwHSVBArhDrlink0r1kqSH8B/Y4wBuucj1nf3sLOhSK6qOqe/TijC/uDmLFRcMWSPmkx bFnWnnPuLiuPewgLzC8CEP+jdDwhfSu/3ZuP+8LPu1fpmPDtQVaAmfn98pLWRRw+IR6+ mC1w== 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:content-transfer-encoding :in-reply-to; bh=KY3/Fe4BV/74ZiMw1TvpKdEkm/AsQHzqLHKHNu/kDmc=; b=MAmaZO/sruQxOD8s9swFJF9p1FDP1CXzuW1LjABulJnouJm+ZHUz+irSYTeta5e6xS kK0xogH8NDS3Eho3JTxlZXjiX78/av6Hx8eVh3cEalrzbg6JN/ep8gsH/igYMVWI+XLw PsKsf7UPUWHT5k2xt5+4jRpL+mHVsfOGA3KeIM71Fdyhb0NKTMWXy3+InBK00l3ekT3V 8tOykAbIH9je0WzJuT6voA2Rey3W8SisNpsK09F1yzwfpIIriMKOaZWcxhXXrWb/M7lA wkDFt6gAvH0+V6TLDoAXKjYb9KgUDzj6LBK6MNof7BsUM/VGcIZArpOAytQVawUqFkea oFWQ== X-Gm-Message-State: AOAM531fWd2Fd1XX2WQ0fL+6C04ZiRvZ1ICVnd7/Vl0420fT2dQlvWNz Rzq10fSajOhDozTQH1TQxdM= X-Google-Smtp-Source: ABdhPJyI9zCBxYoyemmWoqLLLLzW0K6IFRxsRqdNiqPZgF5KHNNKTYIZjik/bU/acmKbQCRPSdCPdQ== X-Received: by 2002:a17:907:1b1b:: with SMTP id mp27mr28891474ejc.538.1632157430972; Mon, 20 Sep 2021 10:03:50 -0700 (PDT) Received: from skbuf ([82.78.148.104]) by smtp.gmail.com with ESMTPSA id di4sm7351967edb.34.2021.09.20.10.03.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Sep 2021 10:03:50 -0700 (PDT) Date: Mon, 20 Sep 2021 20:03:48 +0300 From: Vladimir Oltean To: Florian Fainelli Cc: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , Network Development , Andrew Lunn , Heiner Kallweit , Russell King , Saravana Kannan Subject: Re: Race between "Generic PHY" and "bcm53xx" drivers after -EPROBE_DEFER Message-ID: <20210920170348.o7u66gpwnh7bczu2@skbuf> References: <3639116e-9292-03ca-b9d9-d741118a4541@gmail.com> <4648f65c-4d38-dbe9-a902-783e6dfb9cbd@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4648f65c-4d38-dbe9-a902-783e6dfb9cbd@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Sep 20, 2021 at 09:36:23AM -0700, Florian Fainelli wrote: > +Andrew, Vladimir, Heiner, Russell, Saravana, > > On 9/20/21 5:52 AM, Rafał Miłecki wrote: > > I have problem using a switch b53 MDIO driver with an Ethernet bgmac > > driver. > > > > bgmac registers MDIO bus before registering Ethernet controller. That > > results in kernel probing switch (available as MDIO device) early which > > results in dsa_port_parse_of() returning -EPROBE_DEFER. > > Yes, putting the big picture together and assuming you have applied > these 3 patches which is how you observed that: > > https://lore.kernel.org/linux-devicetree/20210920123441.9088-1-zajec5@gmail.com/ > https://lore.kernel.org/linux-devicetree/20210920141024.1409-1-zajec5@gmail.com/ > https://lore.kernel.org/linux-devicetree/20210920141024.1409-2-zajec5@gmail.com/ > > This is somewhat expected unfortunately and I don't know how we can > break the circular dependencies here. Why is it expected? AFAIK: (1) the Generic PHY driver will not match any hardware in phy_bus_match, it is only bound by hand. Am I wrong? (2) of_mdiobus_register sets "mdio->phy_mask = ~0;" anyway, which blocks the automatic creation of any phy_device for stuff that responds to PHY ID registers 2 and 3. > > It's OK so far but then in goes like this: > > > > [    1.306884] bus: 'bcma': driver_probe_device: matched device bcma0:5 with driver bgmac_bcma > > [    1.315427] bus: 'bcma': really_probe: probing driver bgmac_bcma with device bcma0:5 > > [    1.323468] bgmac_bcma bcma0:5: Found PHY addr: 30 (NOREGS) > > [    1.329722] libphy: bcma_mdio mii bus: probed > > [    1.334468] bus: 'mdio_bus': driver_probe_device: matched device bcma_mdio-0-0:1e with driver bcm53xx > > [    1.343877] bus: 'mdio_bus': really_probe: probing driver bcm53xx with device bcma_mdio-0-0:1e > > [    1.353174] bcm53xx bcma_mdio-0-0:1e: found switch: BCM53125, rev 4 > > [    1.359595] bcm53xx bcma_mdio-0-0:1e: failed to register switch: -517 > > [    1.366212] mdio_bus bcma_mdio-0-0:1e: Driver bcm53xx requests probe deferral > > [    1.373499] mdio_bus bcma_mdio-0-0:1e: Added to deferred list > > [    1.379362] bgmac_bcma bcma0:5: Support for Roboswitch not implemented > > [    1.387067] bgmac_bcma bcma0:5: Timeout waiting for reg 0x1E0 > > [    1.393600] driver: 'Generic PHY': driver_bound: bound to device 'bcma_mdio-0-0:1e' > > [    1.401390] Generic PHY bcma_mdio-0-0:1e: Removed from deferred list > > > > I can't drop "Generic PHY" driver as it's required for non-CPU switch > > ports. I just need kernel to prefer b53 MDIO driver over the "Generic > > PHY" one. > > > > Can someone help me fix that, please? > > I don't think that you have a race condition, but you have the Ethernet > switch's pseudo PHY what's a pseudo PHY? > which is accessible via MDIO and the Generic PHY driver happily goes > on trying to read the MII_PHYSID1/PHYS_ID2 which do not map to > anything on that switch, but still you will get a non-zero/non-all Fs > value from there, hence the Generic PHY is happy to take over. Why would it do that? Why would there be a PHY device created for the switch? Is there any phy-handle pointing to the switch OF node? > Given that the MDIO node does have a compatible string which is not in > the form of an Ethernet PHY's compatible string, I wonder if we can > somewhat break the circular dependency using that information. I think you're talking about: of_mdiobus_register -> of_mdiobus_child_is_phy but as mentioned, that code path should not be creating PHY devices. I think this code path in bgmac_probe might be responsible for it: switch (core->core_unit) { case 0: bgmac->phyaddr = sprom->et0phyaddr; break; case 1: bgmac->phyaddr = sprom->et1phyaddr; break; case 2: bgmac->phyaddr = sprom->et2phyaddr; break; } bgmac->phyaddr &= BGMAC_PHY_MASK; if (bgmac->phyaddr == BGMAC_PHY_MASK) { dev_err(bgmac->dev, "No PHY found\n"); err = -ENODEV; goto err; } dev_info(bgmac->dev, "Found PHY addr: %d%s\n", bgmac->phyaddr, bgmac->phyaddr == BGMAC_PHY_NOREGS ? " (NOREGS)" : ""); if (!bgmac_is_bcm4707_family(core) && !(ci->id == BCMA_CHIP_ID_BCM53573 && core->core_unit == 1)) { struct phy_device *phydev; mii_bus = bcma_mdio_mii_register(bgmac); if (IS_ERR(mii_bus)) { err = PTR_ERR(mii_bus); goto err; } bgmac->mii_bus = mii_bus; phydev = mdiobus_get_phy(bgmac->mii_bus, bgmac->phyaddr); if (ci->id == BCMA_CHIP_ID_BCM53573 && phydev && (phydev->drv->phy_id & phydev->drv->phy_id_mask) == PHY_ID_BCM54210E) phydev->dev_flags |= PHY_BRCM_EN_MASTER_MODE; } At least, that's what the log indicates: [    1.323468] bgmac_bcma bcma0:5: Found PHY addr: 30 (NOREGS) <- 30 is 0x1e, which is Rafal's switch MDIO address in the device tree patch here: https://lore.kernel.org/linux-devicetree/20210920141024.1409-1-zajec5@gmail.com/ So I haven't investigated what the code tries to do by searching the "sprom", but it probably shouldn't have a PHY address pointing towards the switch?