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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 7AFD3C433F5 for ; Fri, 17 Sep 2021 16:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 629CF61108 for ; Fri, 17 Sep 2021 16:32:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233029AbhIQQeL (ORCPT ); Fri, 17 Sep 2021 12:34:11 -0400 Received: from foss.arm.com ([217.140.110.172]:55128 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231351AbhIQQeL (ORCPT ); Fri, 17 Sep 2021 12:34:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E3E62101E; Fri, 17 Sep 2021 09:32:48 -0700 (PDT) Received: from e107158-lin (e107158-lin.cambridge.arm.com [10.1.194.47]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E116D3F59C; Fri, 17 Sep 2021 09:32:47 -0700 (PDT) Date: Fri, 17 Sep 2021 17:32:45 +0100 From: Qais Yousef To: "Paul E. McKenney" Cc: Fabio Estevam , Kalle Valo , ath10k@lists.infradead.org, linux-mmc , Ulf Hansson , Marek Vasut Subject: Re: NOHZ tick-stop error with ath10k SDIO Message-ID: <20210917163245.f53fh2nuswqlkwgw@e107158-lin> References: <20210818154358.GS4126399@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210818154358.GS4126399@paulmck-ThinkPad-P17-Gen-1> Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Hi Paul On 08/18/21 08:43, Paul E. McKenney wrote: > On Wed, Aug 18, 2021 at 12:18:25PM -0300, Fabio Estevam wrote: > > Hi, > > > > When launching the hostapd application on a i.MX7 based board with an > > ath10k device connected via SDIO, the following "NOHZ tick-stop error" > > messages are seen: > > > > # hostapd /etc/wifi.conf > > Configuration file: /etc/wifi.conf > > wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE > > [ 63.021149] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > Using interface wlan0 with hwaddr 00:1f:7b:31:04:a0 and ssid "thessid" > > [ 67.332470] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready > > wlan0: interface state COUNTRY_UPDATE->ENABLED > > wlan0: AP-ENABLED > > [ 68.025845] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 69.025973] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 69.607432] cfg80211: failed to load regulatory.db > > [ 72.026748] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 73.027039] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 74.027159] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 75.027109] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 76.027461] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 77.027391] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 78.027560] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > > > This happens on all kernel versions from 5.10 to 5.13. > > > > Any ideas on how to fix this problem? > > I believe that you need this commit (and possibly some prerequsites): > > 47c218dcae65 ("tick/sched: Prevent false positive softirq pending warnings on RT") > > Adding Qais on CC for his thoughts. Sorry for the late response. A combination of holidays and sickness kept me away from email for a while. I did see an issue on 5.10 recently but I was running android kernel. I thought initially the problem is similar to the upstream one we were seeing on mainline for a while in the past but it turned out a genuine bug due to a patch that tries to 'fix' softirq interference with RT. Reverting that patch fixed the issue for me. It turned out later that it was specific to the platform I was running on and it's not reproducible by others on other platforms. Upstream 5.10-LTS was fine for me. HTH. Thanks -- Qais Yousef 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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 DFE15C433F5 for ; Fri, 17 Sep 2021 16:33:01 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AB44161019 for ; Fri, 17 Sep 2021 16:33:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org AB44161019 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iCDeGFGsFN9HAUipeITp06kwZCMWYUw2VxcttpXYu2o=; b=oIpiuFvUe0Uyql jNmIghISGr+ACrrqW8GDE2mJPej+H76ABVMBfpe6jgfdpllaCesOkO+D4T1f4uY8MPDRvLP4+polC 1ONbbQwmprviCC9iZiByJdlO+pAGMQr/xN3XztiBxd5ua5cCnbr3/t/XAIKB/Ei1M1u7EnhxR8zrG /J48UKfGOghbX/9WH+e3vQa1vdONRHp4NXTzrDuA8rMbp887BFV5LGndp2HON/ibE97wnZIQn4ur9 YIXhVwI6CrqUwCbpQJxfGsTGm4j+auzJy/EZb+7Fex3fB7UMtaEpmmICnNHVUIO2GQ0QgFMDWcbv8 /lI+As7NOzeFghnmuqsQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRGnJ-00EeJf-Ec; Fri, 17 Sep 2021 16:32:57 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRGnG-00EeI9-Bj for ath10k@lists.infradead.org; Fri, 17 Sep 2021 16:32:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E3E62101E; Fri, 17 Sep 2021 09:32:48 -0700 (PDT) Received: from e107158-lin (e107158-lin.cambridge.arm.com [10.1.194.47]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E116D3F59C; Fri, 17 Sep 2021 09:32:47 -0700 (PDT) Date: Fri, 17 Sep 2021 17:32:45 +0100 From: Qais Yousef To: "Paul E. McKenney" Cc: Fabio Estevam , Kalle Valo , ath10k@lists.infradead.org, linux-mmc , Ulf Hansson , Marek Vasut Subject: Re: NOHZ tick-stop error with ath10k SDIO Message-ID: <20210917163245.f53fh2nuswqlkwgw@e107158-lin> References: <20210818154358.GS4126399@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210818154358.GS4126399@paulmck-ThinkPad-P17-Gen-1> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210917_093254_492507_5F4E8AD7 X-CRM114-Status: GOOD ( 19.84 ) X-BeenThere: ath10k@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+ath10k=archiver.kernel.org@lists.infradead.org Hi Paul On 08/18/21 08:43, Paul E. McKenney wrote: > On Wed, Aug 18, 2021 at 12:18:25PM -0300, Fabio Estevam wrote: > > Hi, > > > > When launching the hostapd application on a i.MX7 based board with an > > ath10k device connected via SDIO, the following "NOHZ tick-stop error" > > messages are seen: > > > > # hostapd /etc/wifi.conf > > Configuration file: /etc/wifi.conf > > wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE > > [ 63.021149] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > Using interface wlan0 with hwaddr 00:1f:7b:31:04:a0 and ssid "thessid" > > [ 67.332470] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready > > wlan0: interface state COUNTRY_UPDATE->ENABLED > > wlan0: AP-ENABLED > > [ 68.025845] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 69.025973] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 69.607432] cfg80211: failed to load regulatory.db > > [ 72.026748] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 73.027039] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 74.027159] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 75.027109] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 76.027461] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 77.027391] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > [ 78.027560] NOHZ tick-stop error: Non-RCU local softirq work is > > pending, handler #08!!! > > > > This happens on all kernel versions from 5.10 to 5.13. > > > > Any ideas on how to fix this problem? > > I believe that you need this commit (and possibly some prerequsites): > > 47c218dcae65 ("tick/sched: Prevent false positive softirq pending warnings on RT") > > Adding Qais on CC for his thoughts. Sorry for the late response. A combination of holidays and sickness kept me away from email for a while. I did see an issue on 5.10 recently but I was running android kernel. I thought initially the problem is similar to the upstream one we were seeing on mainline for a while in the past but it turned out a genuine bug due to a patch that tries to 'fix' softirq interference with RT. Reverting that patch fixed the issue for me. It turned out later that it was specific to the platform I was running on and it's not reproducible by others on other platforms. Upstream 5.10-LTS was fine for me. HTH. Thanks -- Qais Yousef _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k