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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C773C433EF for ; Mon, 14 Feb 2022 10:34:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347203AbiBNKeQ (ORCPT ); Mon, 14 Feb 2022 05:34:16 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:41538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347920AbiBNKdQ (ORCPT ); Mon, 14 Feb 2022 05:33:16 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A174B2BD9; Mon, 14 Feb 2022 02:00:29 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9E3F060C32; Mon, 14 Feb 2022 10:00:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72EA0C340F0; Mon, 14 Feb 2022 10:00:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644832828; bh=TBnyqoTQPosQtBqxYCNdVgHbcUIa0+jxn7HOS9c/KvI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zOpCWNoyowSb3Ji3fjFbd6GQxu28xQ8S5ah7huglGhF0gbdqcOybk9sXwTF8pC0Ad kGuneG199TOqG129RR3zIBN4SEe5AwxLlaZBUr6bW1wWUCeJL98vB56znfZVSg7DWO YhbvJmoyNa70EueGNpZAMdM0sqNepwaZdd+hCR1Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vladimir Oltean , Florian Fainelli , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.16 136/203] net: dsa: bcm_sf2: dont use devres for mdiobus Date: Mon, 14 Feb 2022 10:26:20 +0100 Message-Id: <20220214092514.857178364@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220214092510.221474733@linuxfoundation.org> References: <20220214092510.221474733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vladimir Oltean [ Upstream commit 08f1a20822349004bb9cc1b153ecb516e9f2889d ] As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres") mdiobus_free() will panic when called from devm_mdiobus_free() <- devres_release_all() <- __device_release_driver(), and that mdiobus was not previously unregistered. The Starfighter 2 is a platform device, so the initial set of constraints that I thought would cause this (I2C or SPI buses which call ->remove on ->shutdown) do not apply. But there is one more which applies here. If the DSA master itself is on a bus that calls ->remove from ->shutdown (like dpaa2-eth, which is on the fsl-mc bus), there is a device link between the switch and the DSA master, and device_links_unbind_consumers() will unbind the bcm_sf2 switch driver on shutdown. So the same treatment must be applied to all DSA switch drivers, which is: either use devres for both the mdiobus allocation and registration, or don't use devres at all. The bcm_sf2 driver has the code structure in place for orderly mdiobus removal, so just replace devm_mdiobus_alloc() with the non-devres variant, and add manual free where necessary, to ensure that we don't let devres free a still-registered bus. Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()") Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/dsa/bcm_sf2.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c index 13aa43b5cffd9..1502d200682f8 100644 --- a/drivers/net/dsa/bcm_sf2.c +++ b/drivers/net/dsa/bcm_sf2.c @@ -584,7 +584,7 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds) get_device(&priv->master_mii_bus->dev); priv->master_mii_dn = dn; - priv->slave_mii_bus = devm_mdiobus_alloc(ds->dev); + priv->slave_mii_bus = mdiobus_alloc(); if (!priv->slave_mii_bus) { of_node_put(dn); return -ENOMEM; @@ -644,8 +644,10 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds) } err = mdiobus_register(priv->slave_mii_bus); - if (err && dn) + if (err && dn) { + mdiobus_free(priv->slave_mii_bus); of_node_put(dn); + } return err; } @@ -653,6 +655,7 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds) static void bcm_sf2_mdio_unregister(struct bcm_sf2_priv *priv) { mdiobus_unregister(priv->slave_mii_bus); + mdiobus_free(priv->slave_mii_bus); of_node_put(priv->master_mii_dn); } -- 2.34.1