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=unavailable 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 036ECC35246 for ; Sat, 1 Feb 2020 20:02:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1A552064C for ; Sat, 1 Feb 2020 20:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726718AbgBAUCE (ORCPT ); Sat, 1 Feb 2020 15:02:04 -0500 Received: from foss.arm.com ([217.140.110.172]:43576 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726354AbgBAUCD (ORCPT ); Sat, 1 Feb 2020 15:02:03 -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 ACBC3FEC; Sat, 1 Feb 2020 12:02:02 -0800 (PST) Received: from [192.168.122.164] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5F0663F67D; Sat, 1 Feb 2020 12:02:02 -0800 (PST) Subject: Re: [PATCH 3/6] net: bcmgenet: enable automatic phy discovery To: Andrew Lunn Cc: netdev@vger.kernel.org, opendmb@gmail.com, f.fainelli@gmail.com, davem@davemloft.net, bcm-kernel-feedback-list@broadcom.com, linux-kernel@vger.kernel.org, wahrenst@gmx.net, hkallweit1@gmail.com References: <20200201074625.8698-1-jeremy.linton@arm.com> <20200201074625.8698-4-jeremy.linton@arm.com> <20200201152518.GI9639@lunn.ch> From: Jeremy Linton Message-ID: Date: Sat, 1 Feb 2020 14:02:01 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200201152518.GI9639@lunn.ch> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2/1/20 9:25 AM, Andrew Lunn wrote: > On Sat, Feb 01, 2020 at 01:46:22AM -0600, Jeremy Linton wrote: >> The unimac mdio driver falls back to scanning the >> entire bus if its given an appropriate mask. In ACPI >> mode we expect that the system is well behaved and >> conforms to recent versions of the specification. >> >> We then utilize phy_find_first(), and >> phy_connect_direct() to find and attach to the >> discovered phy during net_device open. >> >> Signed-off-by: Jeremy Linton >> --- >> drivers/net/ethernet/broadcom/genet/bcmmii.c | 40 +++++++++++++++++--- >> 1 file changed, 34 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c >> index 2049f8218589..f3271975b375 100644 >> --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c >> +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c >> @@ -5,7 +5,7 @@ >> * Copyright (c) 2014-2017 Broadcom >> */ >> >> - >> +#include >> #include >> #include >> #include >> @@ -311,7 +311,9 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) >> int bcmgenet_mii_probe(struct net_device *dev) >> { >> struct bcmgenet_priv *priv = netdev_priv(dev); >> - struct device_node *dn = priv->pdev->dev.of_node; >> + struct device *kdev = &priv->pdev->dev; >> + struct device_node *dn = kdev->of_node; >> + >> struct phy_device *phydev; >> u32 phy_flags = 0; >> int ret; >> @@ -334,7 +336,27 @@ int bcmgenet_mii_probe(struct net_device *dev) >> return -ENODEV; >> } >> } else { >> - phydev = dev->phydev; >> + if (has_acpi_companion(kdev)) { >> + char mdio_bus_id[MII_BUS_ID_SIZE]; >> + struct mii_bus *unimacbus; >> + >> + snprintf(mdio_bus_id, MII_BUS_ID_SIZE, "%s-%d", >> + UNIMAC_MDIO_DRV_NAME, priv->pdev->id); >> + >> + unimacbus = mdio_find_bus(mdio_bus_id); >> + if (!unimacbus) { >> + pr_err("Unable to find mii\n"); >> + return -ENODEV; >> + } >> + phydev = phy_find_first(unimacbus); >> + put_device(&unimacbus->dev); >> + if (!phydev) { >> + pr_err("Unable to find PHY\n"); >> + return -ENODEV; > > Hi Jeremy > > phy_find_first() is not recommended. Only use it if you have no other > option. If the hardware is more complex, two PHYs on one bus, you are > going to have a problem. So i suggest this is used only for PCI cards > where the hardware is very fixed, and there is only ever one MAC and > PHY on the PCI card. When you do have this split between MAC and MDIO > bus, each being independent devices, it is more likely that you do > have multiple PHYs on one shared MDIO bus. > > In the DT world, you use a phy-handle to point to the PHY node in the > device tree. Does ACPI have the same concept, a pointer to some other > device in ACPI? I though I should clarify the direct question here about ACPI. ACPI does have the ability to do what you describe, but it a more rigorous way. If you look at the ACPI GenericSerialBus abstraction you will see how ACPI would likely handle this situation. I've been considering making a similar comment in that large fwnode patch set posted the other day.