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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF0B6C433FE for ; Mon, 18 Apr 2022 14:17:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344039AbiDROU0 (ORCPT ); Mon, 18 Apr 2022 10:20:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344506AbiDROSH (ORCPT ); Mon, 18 Apr 2022 10:18:07 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24DF047AF5; Mon, 18 Apr 2022 06:13:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E674EB80EEA; Mon, 18 Apr 2022 13:13:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B54BC385A7; Mon, 18 Apr 2022 13:13:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650287596; bh=2SO/WK+/OcnDbPUELASOfoynAAfaA8Zv+4kTfAUH8VU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=y0fhgC7MQT/uLj8+DN61G/18iTSITXK5S8/VKF+ZstU0V7UOw4RTe6V2bgZq7Pu22 N6qwiui6BmxW/mThenJ52sqGEnfMKjRbK9zHP38r7nZt7Dl54Aappgi8U4/tCKSXYQ Cb0cxzBpc0oA8fqfQfQHvt9ZZDTi9r4TeecSFYqc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Guanghui , Will Deacon , Sasha Levin Subject: [PATCH 4.9 171/218] iommu/arm-smmu-v3: fix event handling soft lockup Date: Mon, 18 Apr 2022 14:13:57 +0200 Message-Id: <20220418121205.435740005@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121158.636999985@linuxfoundation.org> References: <20220418121158.636999985@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhou Guanghui [ Upstream commit 30de2b541af98179780054836b48825fcfba4408 ] During event processing, events are read from the event queue one by one until the queue is empty.If the master device continuously requests address access at the same time and the SMMU generates events, the cyclic processing of the event takes a long time and softlockup warnings may be reported. arm-smmu-v3 arm-smmu-v3.34.auto: event 0x0a received: arm-smmu-v3 arm-smmu-v3.34.auto: 0x00007f220000280a arm-smmu-v3 arm-smmu-v3.34.auto: 0x000010000000007e arm-smmu-v3 arm-smmu-v3.34.auto: 0x00000000034e8670 watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [irq/268-arm-smm:247] Call trace: _dev_info+0x7c/0xa0 arm_smmu_evtq_thread+0x1c0/0x230 irq_thread_fn+0x30/0x80 irq_thread+0x128/0x210 kthread+0x134/0x138 ret_from_fork+0x10/0x1c Kernel panic - not syncing: softlockup: hung tasks Fix this by calling cond_resched() after the event information is printed. Signed-off-by: Zhou Guanghui Link: https://lore.kernel.org/r/20220119070754.26528-1-zhouguanghui1@huawei.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/arm-smmu-v3.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 48d382008788..db40ce599e97 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1171,6 +1171,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) dev_info(smmu->dev, "\t0x%016llx\n", (unsigned long long)evt[i]); + cond_resched(); } /* -- 2.35.1