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=-14.2 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,INCLUDES_PATCH, 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 22EC1C47076 for ; Fri, 21 May 2021 16:52:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F023561090 for ; Fri, 21 May 2021 16:52:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237735AbhEUQxW (ORCPT ); Fri, 21 May 2021 12:53:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230471AbhEUQxU (ORCPT ); Fri, 21 May 2021 12:53:20 -0400 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8410AC061574; Fri, 21 May 2021 09:51:57 -0700 (PDT) Received: by mail-pf1-x431.google.com with SMTP id x18so11038338pfi.9; Fri, 21 May 2021 09:51:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=fvVKZIh08je3V7R57Yy3qgYSEUd5usbVkYa2j9NtTvI=; b=ECakFYMpqdrwjwDhbEDysTwyFEuOK4nvyYfIKeZsuiVs8l2bJc6tkJi8nHWIGmGflx CClQfiUpo2+cN1aSF8W/R7TAm0W9GeXSCkkky48O5JGYntoxqiTlczoUS9HN0hx23TsA 4PA6p0YWQYap4vdXyX8XFPn0WkzFIA2NOOox+c874qL7ChxlPH8THgpMQEVv/K1ylIXM BcAIcU4sx5g8fStVeQncfvfBHknPd0OOP51PuUjM6KFc6eoYlRMvX+hzYh0wSc/45cdw aCdQJVLeh9sdFSaBPQnRQ1YjhXfX/KPt9gZN/553XKKdGHa1cebBYjffkePI36pA6qkd QsbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=fvVKZIh08je3V7R57Yy3qgYSEUd5usbVkYa2j9NtTvI=; b=RV5aYLlsZBcdTrkrincPUW2KsKvW4nLkjIRNpdG2OdUprXV0oFxTkCyXOiEimjIVzl gSflafctA/JxtJLP4BgGH1XXjjBHBw5KragXYIR/CgzKWo/N2Sdl9GoIBOvMfC8pQX9o vOzrCzT0c2SHwbPD2x4whGeJG0iQvQmiq2FIbUusPajLUOlU+0i3wENIGRpPOyT9bXBO yLwdZ9e56pvLgSWAfq6rRB2iPkZ1BuTUH7fMwXcpeh+3MaHSma/Uj1lofNVFDbor7sBg orSPzU0XyU+Pop6qBXY0GZ+5OTylvuiq1CGxT5T49DkhK8yS0bU/VVCdZssCLAmBX+Sq qreA== X-Gm-Message-State: AOAM532CHt3PDkK8FVmLwr5oHdIWpaAm0lxOMxpTUr2xlYAdq9lISPls XPFwHcfs5Saf4XOdYmZzqt4= X-Google-Smtp-Source: ABdhPJzog69dC6PiYJE/OJf2iYLaUtAZO9F2WqIysgASxjem1UQTGQg7xPYvszEfYAuPlJRBb54fXw== X-Received: by 2002:aa7:8010:0:b029:254:f083:66fa with SMTP id j16-20020aa780100000b0290254f08366famr11332600pfi.17.1621615917028; Fri, 21 May 2021 09:51:57 -0700 (PDT) Received: from [10.230.29.202] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id u7sm3580352pjc.16.2021.05.21.09.51.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 May 2021 09:51:56 -0700 (PDT) Subject: Re: [PATCH] net: macb: ensure the device is available before accessing GEMGXL control registers To: Zong Li , nicolas.ferre@microchip.com, claudiu.beznea@microchip.com, davem@davemloft.net, kuba@kernel.org, palmer@dabbelt.com, paul.walmsley@sifive.com, schwab@linux-m68k.org, sboyd@kernel.org, aou@eecs.berkeley.edu, mturquette@baylibre.com, geert@linux-m68k.org, yixun.lan@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org References: <20210521124859.101012-1-zong.li@sifive.com> From: Florian Fainelli Message-ID: Date: Fri, 21 May 2021 09:51:46 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <20210521124859.101012-1-zong.li@sifive.com> 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 5/21/2021 5:48 AM, Zong Li wrote: > If runtime power menagement is enabled, the gigabit ethernet PLL would > be disabled after macb_probe(). During this period of time, the system > would hang up if we try to access GEMGXL control registers. > > We can't put runtime_pm_get/runtime_pm_put/ there due to the issue of > sleep inside atomic section (7fa2955ff70ce453 ("sh_eth: Fix sleeping > function called from invalid context"). Add the similar flag to ensure > the device is available before accessing GEMGXL device. > > Signed-off-by: Zong Li > --- > drivers/net/ethernet/cadence/macb.h | 2 ++ > drivers/net/ethernet/cadence/macb_main.c | 7 +++++++ > 2 files changed, 9 insertions(+) > > diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h > index d8d87213697c..acf5242ce715 100644 > --- a/drivers/net/ethernet/cadence/macb.h > +++ b/drivers/net/ethernet/cadence/macb.h > @@ -1309,6 +1309,8 @@ struct macb { > > u32 rx_intr_mask; > > + unsigned int is_opened; > + > struct macb_pm_data pm_data; > const struct macb_usrio_config *usrio; > }; > diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c > index 6bc7d41d519b..e079ed10ad91 100644 > --- a/drivers/net/ethernet/cadence/macb_main.c > +++ b/drivers/net/ethernet/cadence/macb_main.c > @@ -2781,6 +2781,8 @@ static int macb_open(struct net_device *dev) > if (bp->ptp_info) > bp->ptp_info->ptp_init(dev); > > + bp->is_opened = 1; > + > return 0; > > reset_hw: > @@ -2818,6 +2820,8 @@ static int macb_close(struct net_device *dev) > if (bp->ptp_info) > bp->ptp_info->ptp_remove(dev); > > + bp->is_opened = 0; > + > pm_runtime_put(&bp->pdev->dev); > > return 0; > @@ -2867,6 +2871,9 @@ static struct net_device_stats *gem_get_stats(struct macb *bp) > struct gem_stats *hwstat = &bp->hw_stats.gem; > struct net_device_stats *nstat = &bp->dev->stats; > > + if (!bp->is_opened) > + return nstat; The canonical way to do this check is to use netif_running(), and not open code a boolean tracking whether a network device is opened or not. -- Florian