From patchwork Wed Aug 4 21:43:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saravana Kannan X-Patchwork-Id: 492721 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 49103C432BE for ; Wed, 4 Aug 2021 21:43:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33C4260F94 for ; Wed, 4 Aug 2021 21:43:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232954AbhHDVoD (ORCPT ); Wed, 4 Aug 2021 17:44:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233805AbhHDVn7 (ORCPT ); Wed, 4 Aug 2021 17:43:59 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B03E5C06179A for ; Wed, 4 Aug 2021 14:43:46 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id 18-20020a05620a0792b02903b8e915ccceso2874923qka.18 for ; Wed, 04 Aug 2021 14:43:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Rynpga3J+xjZzUqZXpOXfkfOoHAVyRGf/PRkioLCwmY=; b=B8/MlBGQclT50fb7n0ieBcTHQoZD+gRQ/u345in6OYabDUyr30L+tBW1j2xiCfNLr7 a1C8CtX5vMQRm7x1CDvBkHnR7zdve2JnoVx+Z7xbdcxfV8yk3pWdXvh+j8UYSWjpIiG6 rQTgFQZx6M0HcZUL+vGBw04INfBrgmBHJ2l9jkRxNUionVIyWBvYuy2oGjIubI+Tp0Yo XGhjEY7KB+c3EYjb5InTMJ/2ppIb+GcWeznUvm2v3ZPxxskJbztyZsN3GfzDLyk9Mh31 WWLv+LGc6qcqeKBXZiBeJ7l+m+i/DGhYActbYEasEVcdsi3dwW04HAEC2deDco3mysZ3 YMOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Rynpga3J+xjZzUqZXpOXfkfOoHAVyRGf/PRkioLCwmY=; b=YPW9fMM85CUFtBrkE86xPvMwMJ1XcqwG0X42DTiAxzsAcCVUL8irGcLpmYgG/kMcAz aTKPs5Bt56TbfuOiMJYcjX5fm/cxH1Jp2FXdK1rgLR4whdAARXgO0vN7p29SNK1FGJ7o W0G1Dw7mRdAeC9UurDiVZApLYFUYnFlpFBukQIB5AIXKaPK+Zicd4stPmY4EAlwwbmKp hH1yTjmTNvo28/ctYcKSWMfeegjaWd+/E6b7SdRbxa/0zL2EF65WDrFLuDqpTSTSmP4O x6r44fdpulhHSrRFO1Jhe4oytoj/MRRvl3i2HBt3K5cTBCkMNtR9wBTuTXPtIKyYqV5l Nh7w== X-Gm-Message-State: AOAM533hTJQsJoyEQWRtyR01cpbEdAZmEnTM3k473z+wEiQ5TJiC8MgC 48FdBWQjW6PoRgHZCZM2zELiK4LQFB7wT0E= X-Google-Smtp-Source: ABdhPJzlOYEDH8yob9gAEtyiJ+2bW8yWLnsn+Oa2Ym13tfciy/2gVuwXNkqzQileftC8X7uEAeOaOlgtP57eeUw= X-Received: from saravanak.san.corp.google.com ([2620:15c:2d:3:ffe5:1245:526e:3189]) (user=saravanak job=sendgmr) by 2002:ad4:40cb:: with SMTP id x11mr1616861qvp.60.1628113425608; Wed, 04 Aug 2021 14:43:45 -0700 (PDT) Date: Wed, 4 Aug 2021 14:43:32 -0700 In-Reply-To: <20210804214333.927985-1-saravanak@google.com> Message-Id: <20210804214333.927985-4-saravanak@google.com> Mime-Version: 1.0 References: <20210804214333.927985-1-saravanak@google.com> X-Mailer: git-send-email 2.32.0.554.ge1b32706d8-goog Subject: [PATCH v1 3/3] net: mdio-mux: Handle -EPROBE_DEFER correctly From: Saravana Kannan To: Andrew Lunn , Heiner Kallweit , Russell King , "David S. Miller" , Jakub Kicinski Cc: Saravana Kannan , Marc Zyngier , Neil Armstrong , Kevin Hilman , kernel-team@android.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When registering mdiobus children, if we get an -EPROBE_DEFER, we shouldn't ignore it and continue registering the rest of the mdiobus children. This would permanently prevent the deferring child mdiobus from working instead of reattempting it in the future. So, if a child mdiobus needs to be reattempted in the future, defer the entire mdio-mux initialization. This fixes the issue where PHYs sitting under the mdio-mux aren't initialized correctly if the PHY's interrupt controller is not yet ready when the mdio-mux is being probed. Additional context in the link below. Link: https://lore.kernel.org/lkml/CAGETcx95kHrv8wA-O+-JtfH7H9biJEGJtijuPVN0V5dUKUAB3A@mail.gmail.com/#t Signed-off-by: Saravana Kannan Reviewed-by: Andrew Lunn --- drivers/net/mdio/mdio-mux.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/mdio/mdio-mux.c b/drivers/net/mdio/mdio-mux.c index 13035e2685c4..ebd001f0eece 100644 --- a/drivers/net/mdio/mdio-mux.c +++ b/drivers/net/mdio/mdio-mux.c @@ -175,11 +175,15 @@ int mdio_mux_init(struct device *dev, cb->mii_bus->write = mdio_mux_write; r = of_mdiobus_register(cb->mii_bus, child_bus_node); if (r) { + mdiobus_free(cb->mii_bus); + if (r == -EPROBE_DEFER) { + ret_val = r; + goto err_loop; + } + devm_kfree(dev, cb); dev_err(dev, "Error: Failed to register MDIO bus for child %pOF\n", child_bus_node); - mdiobus_free(cb->mii_bus); - devm_kfree(dev, cb); } else { cb->next = pb->children; pb->children = cb;