From patchwork Thu Jul 2 01:32:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanley Chu X-Patchwork-Id: 11637645 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 895606C1 for ; Thu, 2 Jul 2020 01:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B3482082F for ; Thu, 2 Jul 2020 01:32:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="CgwZgTOh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729096AbgGBBck (ORCPT ); Wed, 1 Jul 2020 21:32:40 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:32759 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728551AbgGBBcj (ORCPT ); Wed, 1 Jul 2020 21:32:39 -0400 X-UUID: 362059a602234cf295d44ba4d16ec340-20200702 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=Fi9mrlEmH73T+Qs6zhoiNlw3NLg/Wea1yifZo8JP4Y0=; b=CgwZgTOhBxzcJIIsXa1MesRryiPmjqC2lXgtysirnwkJ1Xsey+fsObHbO3yYDM+QY7wYeMLonWegUj8sTU7RByWh/LN13iAEPyohjXt8+AOKEZ4OaipRhRC9ZWsEB2djGRmfbiuZlC+0AX0J1RKwW3fSwz/whxBtTqc8vCI0kWQ=; X-UUID: 362059a602234cf295d44ba4d16ec340-20200702 Received: from mtkcas10.mediatek.inc [(172.21.101.39)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 261882455; Thu, 02 Jul 2020 09:32:35 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs02n2.mediatek.inc (172.21.101.101) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 2 Jul 2020 09:32:24 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 2 Jul 2020 09:32:20 +0800 From: Stanley Chu To: , , , , , CC: , , , , , , , , , , , , , Stanley Chu Subject: [RFC PATCH v1] scsi: ufs: Quiesce all scsi devices before shutdown Date: Thu, 2 Jul 2020 09:32:10 +0800 Message-ID: <20200702013210.22958-1-stanley.chu@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-TM-SNTS-SMTP: 18A2182863CD6381535D3CFD5930C92F55638ED85AF7A2AFA65EACC53C1742932000:8 X-MTK: N Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Currently I/O request could be still submitted to UFS device while UFS is working on shutdown flow. This may lead to racing as below scenarios and finally system may crash due to unclocked register accesses. To fix this kind of issues, specifically quiesce all SCSI devices before UFS shutdown to block all I/O request sending from block layer. Example of racing scenario: While UFS device is runtime-suspended Thread #1: Executing UFS shutdown flow, e.g., ufshcd_suspend(UFS_SHUTDOWN_PM) Thread #2: Executing runtime resume flow triggered by I/O request, e.g., ufshcd_resume(UFS_RUNTIME_PM) This breaks the assumption that UFS PM flows can not be running concurrently and thus some unexpected racing behavior may happen. Signed-off-by: Stanley Chu --- drivers/scsi/ufs/ufshcd.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 59358bb75014..cadfa9006972 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -8599,10 +8599,14 @@ EXPORT_SYMBOL(ufshcd_runtime_idle); int ufshcd_shutdown(struct ufs_hba *hba) { int ret = 0; + struct scsi_target *starget; if (!hba->is_powered) goto out; + list_for_each_entry(starget, &hba->host->__targets, siblings) + scsi_target_quiesce(starget); + if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba)) goto out;