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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 40FC8C33C8C for ; Tue, 7 Jan 2020 12:36:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 131BE2467A for ; Tue, 7 Jan 2020 12:36:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728073AbgAGMg1 (ORCPT ); Tue, 7 Jan 2020 07:36:27 -0500 Received: from foss.arm.com ([217.140.110.172]:57146 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727177AbgAGMg0 (ORCPT ); Tue, 7 Jan 2020 07:36:26 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E992331B; Tue, 7 Jan 2020 04:36:25 -0800 (PST) Received: from [10.1.196.37] (e121345-lin.cambridge.arm.com [10.1.196.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 188593F534; Tue, 7 Jan 2020 04:36:22 -0800 (PST) Subject: Re: [PATCH net] Revert "net: stmmac: platform: Fix MDIO init for platforms without PHY" To: Sriram Dash , 'Florian Fainelli' , netdev@vger.kernel.org, narmstrong@baylibre.com, 'Heiko Stuebner' Cc: 'Jose Abreu' , 'Jayati Sahu' , 'Alexandre Torgue' , tomeu.vizoso@collabora.com, rcsekar@samsung.com, khilman@baylibre.com, mgalka@collabora.com, linux-kernel@vger.kernel.org, 'Padmanabhan Rajanbabu' , linux-stm32@st-md-mailman.stormreply.com, broonie@kernel.org, pankaj.dubey@samsung.com, 'Maxime Coquelin' , guillaume.tucker@collabora.com, enric.balletbo@collabora.com, 'Giuseppe Cavallaro' , "'David S. Miller'" , linux-arm-kernel@lists.infradead.org References: <20200107050846.16838-1-f.fainelli@gmail.com> <011a01d5c51d$d7482290$85d867b0$@samsung.com> <59cb4087-6a71-9684-c4cf-d203600b45a9@arm.com> <014001d5c553$ff7f06d0$fe7d1470$@samsung.com> From: Robin Murphy Message-ID: <71256455-6cfe-a19e-1c48-17bded1903f8@arm.com> Date: Tue, 7 Jan 2020 12:36:21 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <014001d5c553$ff7f06d0$fe7d1470$@samsung.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/01/2020 12:14 pm, Sriram Dash wrote: >> From: Robin Murphy >> Subject: Re: [PATCH net] Revert "net: stmmac: platform: Fix MDIO init for >> platforms without PHY" >> >> On 07/01/2020 5:46 am, Sriram Dash wrote: >>>> From: Florian Fainelli >>>> Subject: [PATCH net] Revert "net: stmmac: platform: Fix MDIO init for >>> platforms >>>> without PHY" >>>> >>>> This reverts commit d3e014ec7d5ebe9644b5486bc530b91e62bbf624 ("net: >>>> stmmac: platform: Fix MDIO init for platforms without PHY") because >>>> it >>> breaks >>>> existing systems with stmmac which do not have a MDIO bus sub-node >>>> nor a 'phy-handle' property declared in their Device Tree. On those >>>> systems, the stmmac MDIO bus is expected to be created and then >>>> scanned by >>>> of_mdiobus_register() to create PHY devices. >>>> >>>> While these systems should arguably make use of a more accurate >>>> Device >>> Tree >>>> reprensentation with the use of the MDIO bus sub-node an appropriate >>>> 'phy- handle', we cannot break them, therefore restore the behavior >>>> prior to the >>> said >>>> commit. >>>> >>>> Fixes: d3e014ec7d5e ("net: stmmac: platform: Fix MDIO init for >>>> platforms without PHY") >>>> Reported-by: Heiko Stuebner >>>> Reported-by: kernelci.org bot >>>> Signed-off-by: Florian Fainelli >>> Nacked-by: Sriram Dash >>> >>>> --- >>>> Heiko, >>>> >>>> I did not add the Tested-by because the patch is a little bit >>>> different >>> from what >>>> you tested, even if you most likely were not hitting the other part >>>> that I >>> was >>>> changing. Thanks! >>>> >>>> drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >>>> index cc8d7e7bf9ac..bedaff0c13bd 100644 >>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >>>> @@ -320,7 +320,7 @@ static int stmmac_mtl_setup(struct >>>> platform_device *pdev, static int stmmac_dt_phy(struct >> plat_stmmacenet_data *plat, >>>> struct device_node *np, struct device *dev) { >>>> - bool mdio = false; >>>> + bool mdio = true; >>> >>> >>> This is breaking for the platforms with fixed-link. >>> stih418-b2199.dts and 169445.dts to name a few. >>> >>> For the newer platforms, they should provide the mdio/ snps,dwmac-mdio >>> property in the device tree as we are checking the mdio/ >>> snps,dwmac-mdio property in the stmmac_platform driver for the mdio bus >> memory allocation. >>> For existing platforms, I agree we should not break them, but we >>> should make the code correct. And make the existing platforms adapt to the >> proper code. >>> There is a proposed solution. >>> https://protect2.fireeye.com/url?k=d075c0fc-8da69942-d0744bb3-0cc47a31 >>> ba82-60be9f5a0fb38a27&u=https://lkml.org/lkml/2020/1/7/14 >>> >>> What do you think? >> >> The binding says that the phy handle and mdio child node are optional, so >> "update all of the DTBs!" is not a viable solution. I'm far from an expert here, but > > I get your point Robin. Because the mdio child or snps,dwmac-mdio is not mandatory, > there has been this problem. > >> AFAICS the fault of the current code is that it assumes the lack of a phy handle >> implies a fixed link, so the obvious answer is to actually check whether the > > Kind of. > >> "fixed-link" property is present. > > > I agree to have a fixed link check. Possibly this can be done: FWIW, given the 4th case in the kerneldoc table I think this check might need to come first. On the upside, there appears to be a handy helper already, so it may just be as simple as: bool mdio = !of_phy_is_fixed_link(np); Robin. > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c > @@ -320,7 +320,9 @@ static int stmmac_mtl_setup(struct platform_device *pdev, > static int stmmac_dt_phy(struct plat_stmmacenet_data *plat, > struct device_node *np, struct device *dev) > { > - bool mdio = false; > + bool mdio = true; > + struct device_node *fixed_link; > + > static const struct of_device_id need_mdio_ids[] = { > { .compatible = "snps,dwc-qos-ethernet-4.10" }, > {}, > @@ -340,9 +342,8 @@ static int stmmac_dt_phy(struct plat_stmmacenet_data *plat, > } > } > > - if (plat->mdio_node) { > - dev_dbg(dev, "Found MDIO subnode\n"); > - mdio = true; > + if (of_get_child_by_name(np, "fixed-link")) { > + mdio = false; > } > > if (mdio) { > > Neil and Heiko, > > Can you guys please test this on your platforms? > We can post a more cleaner version of the patch if all agree to it. > >> >> Robin. >> >>> >>>> static const struct of_device_id need_mdio_ids[] = { >>>> { .compatible = "snps,dwc-qos-ethernet-4.10" }, >>>> {}, >>>> -- >>>> 2.19.1 >>> >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@lists.infradead.org >>> https://protect2.fireeye.com/url?k=2cb95551-716a0cef-2cb8de1e-0cc47a31 >>> ba82-d01ceb62a8a93fa2&u=http://lists.infradead.org/mailman/listinfo/li >>> nux-arm-kernel >>> >