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=-9.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 5B4D5C433DB for ; Mon, 18 Jan 2021 20:47:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2013822CAD for ; Mon, 18 Jan 2021 20:47:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388445AbhARUpf (ORCPT ); Mon, 18 Jan 2021 15:45:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437971AbhARUlr (ORCPT ); Mon, 18 Jan 2021 15:41:47 -0500 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C74BDC061573; Mon, 18 Jan 2021 12:41:03 -0800 (PST) Received: by mail-pf1-x42e.google.com with SMTP id i63so3793363pfg.7; Mon, 18 Jan 2021 12:41:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=XEt+p0VH0Mt3UDzNuSZ5gd/vonSaeBsHxPfMF1613xI=; b=QVcREkO6E03pZ35t4SFG34ZWgYyV2W8kKK+BslMmfJkLx5kJVYkSlcLCDMwj+r5mXw shKZote+IpwaviD+P+YqhB1AMgQCXplD6w33c6AWRlicidFAzoMdEJ6govm/HVi5e5Ja Ge7Ly4DnZhABPVnxOzizZEmYoSdIhzd/FrsMa55WcmfST1nP35AHOMq2MnAi4aJct4Xh 5+h+/VBN4XzddQLoFX39czJK3Sim+5unr1SfiRWA6zEUtuIFOMBG4LUt9gwRq5m3Qvwc dqmjjGTPkZ/N8uxd1ED9HbqTmyMRY5Obm8hAkLURraCMQZlD/ksorXuZP5+XVtK61MEm rtvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=XEt+p0VH0Mt3UDzNuSZ5gd/vonSaeBsHxPfMF1613xI=; b=e41flBa5aWP1NlgipZDrVd78R6PMRwA8hCs9EJYi/KYLkKCY9WBbPjI54ePKT1d2tW 8k0SraXrBYJ38srOTEbyZQ5a1ed00xigQBx0lI3nGdPfKMdJyP0eTYM6s4edGfDrRJu6 UwXmkCSBxxNJaCqeirjsOpL5qT3nBQQxSaPMsc5VLAYB4InHT5Rrf28YHpw3rLQDjp05 t9Oviz744y9AlhfO5tniBvtgfB2OQV8Rnot21ZlA+0Fqhao/Dx9j9A2y5aUvgRapPMMM l3tGkJwPfINEpJqmNMZjuhLR1dM3KK2ODNxQtNQzHCsu0pvqEI41GywUxGcy5+tScjVQ 6VKg== X-Gm-Message-State: AOAM531GvjM9Lrq/0P++U9U4UCcU9UNye+5pbltUw3ecSV3wBYVpcEnP T212Vjf60qfXa2QwmO6BodfLRyH+oGg= X-Google-Smtp-Source: ABdhPJyLjTYdmagnhqus/gAOrcz1oFASXA/BCZkIAYvcc9kUyRTd6YOSwO3KmLLMrOzpAVAjCjq6Bg== X-Received: by 2002:a63:464a:: with SMTP id v10mr1334521pgk.393.1611002462963; Mon, 18 Jan 2021 12:41:02 -0800 (PST) Received: from [10.230.29.29] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id jx15sm253311pjb.17.2021.01.18.12.41.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 18 Jan 2021 12:41:02 -0800 (PST) Subject: Re: [PATCH net v2 2/2] sh_eth: Make PHY access aware of Runtime PM to fix reboot crash To: Geert Uytterhoeven , Sergei Shtylyov , "David S . Miller" , Jakub Kicinski , Andrew Lunn , Heiner Kallweit , Russell King , Ioana Ciornei , Wolfram Sang Cc: netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210118150656.796584-1-geert+renesas@glider.be> <20210118150656.796584-3-geert+renesas@glider.be> From: Florian Fainelli Message-ID: Date: Mon, 18 Jan 2021 12:40:59 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210118150656.796584-3-geert+renesas@glider.be> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/18/2021 7:06 AM, Geert Uytterhoeven wrote: > Wolfram reports that his R-Car H2-based Lager board can no longer be > rebooted in v5.11-rc1, as it crashes with an imprecise external abort. > The issue can be reproduced on other boards (e.g. Koelsch with R-Car > M2-W) too, if CONFIG_IP_PNP is disabled, and the Ethernet interface is > down at reboot time: > > Unhandled fault: imprecise external abort (0x1406) at 0x00000000 > pgd = (ptrval) > [00000000] *pgd=422b6835, *pte=00000000, *ppte=00000000 > Internal error: : 1406 [#1] ARM > Modules linked in: > CPU: 0 PID: 1105 Comm: init Tainted: G W 5.10.0-rc1-00402-ge2f016cf7751 #1048 > Hardware name: Generic R-Car Gen2 (Flattened Device Tree) > PC is at sh_mdio_ctrl+0x44/0x60 > LR is at sh_mmd_ctrl+0x20/0x24 > ... > Backtrace: > [] (sh_mdio_ctrl) from [] (sh_mmd_ctrl+0x20/0x24) > r7:0000001f r6:00000020 r5:00000002 r4:c22a1dc4 > [] (sh_mmd_ctrl) from [] (mdiobb_cmd+0x38/0xa8) > [] (mdiobb_cmd) from [] (mdiobb_read+0x58/0xdc) > r9:c229f844 r8:c0c329dc r7:c221e000 r6:00000001 r5:c22a1dc4 r4:00000001 > [] (mdiobb_read) from [] (__mdiobus_read+0x74/0xe0) > r7:0000001f r6:00000001 r5:c221e000 r4:c221e000 > [] (__mdiobus_read) from [] (mdiobus_read+0x40/0x54) > r7:0000001f r6:00000001 r5:c221e000 r4:c221e458 > [] (mdiobus_read) from [] (phy_read+0x1c/0x20) > r7:ffffe000 r6:c221e470 r5:00000200 r4:c229f800 > [] (phy_read) from [] (kszphy_config_intr+0x44/0x80) > [] (kszphy_config_intr) from [] (phy_disable_interrupts+0x44/0x50) > r5:c229f800 r4:c229f800 > [] (phy_disable_interrupts) from [] (phy_shutdown+0x18/0x1c) > r5:c229f800 r4:c229f804 > [] (phy_shutdown) from [] (device_shutdown+0x168/0x1f8) > [] (device_shutdown) from [] (kernel_restart_prepare+0x3c/0x48) > r9:c22d2000 r8:c0100264 r7:c0b0d034 r6:00000000 r5:4321fedc r4:00000000 > [] (kernel_restart_prepare) from [] (kernel_restart+0x1c/0x60) > [] (kernel_restart) from [] (__do_sys_reboot+0x168/0x208) > r5:4321fedc r4:01234567 > [] (__do_sys_reboot) from [] (sys_reboot+0x18/0x1c) > r7:00000058 r6:00000000 r5:00000000 r4:00000000 > [] (sys_reboot) from [] (ret_fast_syscall+0x0/0x54) > > As of commit e2f016cf775129c0 ("net: phy: add a shutdown procedure"), > system reboot calls phy_disable_interrupts() during shutdown. As this > happens unconditionally, the PHY registers may be accessed while the > device is suspended, causing undefined behavior, which may crash the > system. > > Fix this by wrapping the PHY bitbang accessors in the sh_eth driver by > wrappers that take care of Runtime PM, to resume the device when needed. > > Reported-by: Wolfram Sang > Suggested-by: Andrew Lunn > Signed-off-by: Geert Uytterhoeven Reviewed-by: Florian Fainelli -- Florian