From patchwork Sat Jan 13 09:22:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?QXLEsW7DpyDDnE5BTA==?= X-Patchwork-Id: 13518924 X-Patchwork-Delegate: kuba@kernel.org Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 583377E9; Sat, 13 Jan 2024 09:22:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arinc9.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arinc9.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arinc9.com header.i=@arinc9.com header.b="TkrNwGzc" Received: by mail.gandi.net (Postfix) with ESMTPSA id 43827C0004; Sat, 13 Jan 2024 09:22:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arinc9.com; s=gm1; t=1705137762; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=mB9WRD6UXawX/aZviJr/LqXnsIPoDNYg4d4Tt1YlqkY=; b=TkrNwGzcmbBNqS3JFQynOg1MmHpaGT+zxUEG3+8ZUGv8+W33RLnTPlHp36SVlk95uDD+nk XWc14sgNS8osRTteaSAPcGEXH8G3jjVCBhnO9mS2dyHhi1VJ0qovlwJ22f27ifdtlS3OON RhpvdcCY+tIhT121P4MuV0oluLVEEu2tCX0nNOb2YfY0gcKC/3xKDEqO73tn9ZOKicohad AVMUeqrACQ8wqPDZjIQaBAHDwNjAUojqXeD9dueDEYRLt5hU+JR4Yk266fgD3gtwBFJU4r 8oB2SmfQ6UeUWzjR0YYZi2O8uy7+mAQc5cyDzXz+UkNw84cn8jb5D6z6w20Uhg== From: =?utf-8?b?QXLEsW7DpyDDnE5BTA==?= To: Andrew Lunn , Florian Fainelli , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: =?utf-8?b?QXLEsW7DpyDDnE5BTA==?= , Luiz Angelo Daros de Luca , mithat.guner@xeront.com, erkin.bozoglu@xeront.com, =?utf-8?q?Alvin_=C5=A0ipraga?= , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH net-next] net: dsa: remove OF-based MDIO bus registration from DSA core Date: Sat, 13 Jan 2024 12:22:11 +0300 Message-Id: <20240113092211.36218-1-arinc.unal@arinc9.com> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-GND-Sasl: arinc.unal@arinc9.com X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC The code block under the "!ds->user_mii_bus && ds->ops->phy_read" check under dsa_switch_setup() populates ds->user_mii_bus. The use of ds->user_mii_bus is inappropriate when the MDIO bus of the switch is described on the device tree [1]. For this reason, use this code block only for switches [with MDIO bus] probed on platform_data, and OF which the switch MDIO bus isn't described on the device tree. Therefore, remove OF-based MDIO bus registration as it's useless for these cases. These subdrivers which control switches [with MDIO bus] probed on OF, will lose the ability to register the MDIO bus OF-based: drivers/net/dsa/b53/b53_common.c drivers/net/dsa/lan9303-core.c drivers/net/dsa/realtek/realtek-mdio.c drivers/net/dsa/vitesse-vsc73xx-core.c These subdrivers let the DSA core driver register the bus: - ds->ops->phy_read() and ds->ops->phy_write() are present. - ds->user_mii_bus is not populated. The commit fe7324b93222 ("net: dsa: OF-ware slave_mii_bus") which brought OF-based MDIO bus registration on the DSA core driver is reasonably recent and, in this time frame, there have been no device trees in the Linux repository that started describing the MDIO bus, or dt-bindings defining the MDIO bus for the switches these subdrivers control. So I don't expect any devices to be affected. The logic we encourage is that all subdrivers should register the switch MDIO bus on their own [2]. And, for subdrivers which control switches [with MDIO bus] probed on OF, this logic must be followed to support all cases properly: No switch MDIO bus defined: Populate ds->user_mii_bus, register the MDIO bus, set the interrupts for PHYs if "interrupt-controller" is defined at the switch node. This case should only be covered for the switches which their dt-bindings documentation didn't document the MDIO bus from the start. This is to keep supporting the device trees that do not describe the MDIO bus on the device tree but the MDIO bus is being used nonetheless. Switch MDIO bus defined: Don't populate ds->user_mii_bus, register the MDIO bus, set the interrupts for PHYs if ["interrupt-controller" is defined at the switch node and "interrupts" is defined at the PHY nodes under the switch MDIO bus node]. Switch MDIO bus defined but explicitly disabled: If the device tree says status = "disabled" for the MDIO bus, we shouldn't need an MDIO bus at all. Instead, just exit as early as possible and do not call any MDIO API. After all subdrivers that control switches with MDIO buses are made to register the MDIO buses on their own, we will be able to get rid of dsa_switch_ops :: phy_read() and :: phy_write(), and the code block for registering the MDIO bus on the DSA core driver. Link: https://lore.kernel.org/netdev/20231213120656.x46fyad6ls7sqyzv@skbuf/ [1] Link: https://lore.kernel.org/netdev/20240103184459.dcbh57wdnlox6w7d@skbuf/ [2] Suggested-by: Luiz Angelo Daros de Luca Signed-off-by: Arınç ÜNAL --- net/dsa/dsa.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index ac7be864e80d..09d2f5d4b3dd 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -626,7 +625,6 @@ static void dsa_switch_teardown_tag_protocol(struct dsa_switch *ds) static int dsa_switch_setup(struct dsa_switch *ds) { - struct device_node *dn; int err; if (ds->setup) @@ -666,10 +664,7 @@ static int dsa_switch_setup(struct dsa_switch *ds) dsa_user_mii_bus_init(ds); - dn = of_get_child_by_name(ds->dev->of_node, "mdio"); - - err = of_mdiobus_register(ds->user_mii_bus, dn); - of_node_put(dn); + err = mdiobus_register(ds->user_mii_bus); if (err < 0) goto free_user_mii_bus; }