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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 9CBDCC43441 for ; Thu, 22 Nov 2018 00:58:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A8F220831 for ; Thu, 22 Nov 2018 00:58:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A8F220831 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391221AbeKVLe4 (ORCPT ); Thu, 22 Nov 2018 06:34:56 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:48924 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730678AbeKVLe4 (ORCPT ); Thu, 22 Nov 2018 06:34:56 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::bf5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id D628613E5BD94; Wed, 21 Nov 2018 16:58:04 -0800 (PST) Date: Wed, 21 Nov 2018 16:58:04 -0800 (PST) Message-Id: <20181121.165804.509539437154732563.davem@davemloft.net> To: vincentc@andestech.com Cc: gregkh@linuxfoundation.org, rdunlap@infradead.org, yuehaibing@huawei.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] net: faraday: ftmac100: remove netif_running(netdev) check before disabling interrupts From: David Miller In-Reply-To: <1542764291-11208-1-git-send-email-vincentc@andestech.com> References: <1542764291-11208-1-git-send-email-vincentc@andestech.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 21 Nov 2018 16:58:05 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vincent Chen Date: Wed, 21 Nov 2018 09:38:11 +0800 > In the original ftmac100_interrupt(), the interrupts are only disabled when > the condition "netif_running(netdev)" is true. However, this condition > causes kerenl hang in the following case. When the user requests to > disable the network device, kernel will clear the bit __LINK_STATE_START > from the dev->state and then call the driver's ndo_stop function. Network > device interrupts are not blocked during this process. If an interrupt > occurs between clearing __LINK_STATE_START and stopping network device, > kernel cannot disable the interrupts due to the condition > "netif_running(netdev)" in the ISR. Hence, kernel will hang due to the > continuous interruption of the network device. > > In order to solve the above problem, the interrupts of the network device > should always be disabled in the ISR without being restricted by the > condition "netif_running(netdev)". > > [V2] > Remove unnecessary curly braces. > > Signed-off-by: Vincent Chen Applied.