From patchwork Tue May 28 08:12:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanley Chu X-Patchwork-Id: 10964099 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D30B392A for ; Tue, 28 May 2019 08:12:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C49AE28644 for ; Tue, 28 May 2019 08:12:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B7ECA2864A; Tue, 28 May 2019 08:12:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5ECC42865F for ; Tue, 28 May 2019 08:12:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=5y5bG9iaUgkW42b7gzrJuUrml/G3pKrlTWiXH6i+k28=; b=dSvV+OS/iy2faV i6N3TUJ9bNb28w48JgXF47Yj4maoBVGNoFot9mAI/jMeEwsyeNx1MQge9HsALugtO0Zdsdlg9v1pw pl1A/KqSqopoXusJGObGjy2Mvx/d+kdYliBhQ/QsUxc/t476JrZldhd29aTjmgJS7C/qgZVQi9/hW N6FtQF6PnwikaNWS+wwrohnd+LvzgYnkS5oyd3Ygy4GJB2skQP/36fBHa2F1HIkt4xM7jh/bHJdZa AeuYyjEY8QfWAizmr5HOQdWv6FoX+NXvL2peAm8hOX8y2yOuyitDHPkH07Mg0h4i5Y2/tAawNrkoG CrGlk4wUC72Ejo/rua4A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hVXDs-0006GY-3n; Tue, 28 May 2019 08:12:40 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hVXDp-0006DL-FA; Tue, 28 May 2019 08:12:38 +0000 X-UUID: 204a2809b9dc4543acc4e344f5a8e4db-20190528 X-UUID: 204a2809b9dc4543acc4e344f5a8e4db-20190528 Received: from mtkcas67.mediatek.inc [(172.29.193.45)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 1883501474; Tue, 28 May 2019 00:12:13 -0800 Received: from MTKMBS01N1.mediatek.inc (172.21.101.68) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 28 May 2019 01:12:12 -0700 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs01n1.mediatek.inc (172.21.101.68) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 28 May 2019 16:12:10 +0800 Received: from mtkswgap22.mediatek.inc (172.21.77.33) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Tue, 28 May 2019 16:12:10 +0800 From: Stanley Chu To: , , , , Subject: [PATCH] scsi: ufs: Use pm_runtime_get_sync in shutdown flow Date: Tue, 28 May 2019 16:12:06 +0800 Message-ID: <1559031126-6587-1-git-send-email-stanley.chu@mediatek.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190528_011237_509075_8D87AD07 X-CRM114-Status: UNSURE ( 9.59 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: marc.w.gonzalez@free.fr, andy.teng@mediatek.com, chun-hung.wu@mediatek.com, kuohong.wang@mediatek.com, evgreen@chromium.org, linux-mediatek@lists.infradead.org, peter.wang@mediatek.com, matthias.bgg@gmail.com, Stanley Chu , linux-arm-kernel@lists.infradead.org, beanhuo@micron.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP There might be a racing issue between UFS shutdown and runtime resume flow described as below, Thread #1: In UFS shutdown flow with ufshcd_shutdown() is running. Thread #2: In UFS runtime-resume flow which invokes ufshcd_runtime_resume() because UFS was in runtime-suspended state while an I/O request was issued. In this scenario, racing may happen and possibly lead to system hang if Thread #2 accesses UFS host's register map after host's resource, like power or clocks, are disabled by Thread #1. To avoid this racing, use PM public function pm_runtime_get_sync() in shutdown flow instead of internal function ufshcd_runtime_resume() for consolidated control of RPM status. One concern is that pm_runtime_get_sync() may be better paired with pm_runtime_put_sync(), however shutdown could be one-way path thus the pairing is not required. Signed-off-by: Stanley Chu Signed-off-by: Peter Wang --- drivers/scsi/ufs/ufshcd.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a208589426b1..cce7303f8653 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -8095,11 +8095,8 @@ int ufshcd_shutdown(struct ufs_hba *hba) if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba)) goto out; - if (pm_runtime_suspended(hba->dev)) { - ret = ufshcd_runtime_resume(hba); - if (ret) - goto out; - } + if (pm_runtime_get_sync(hba->dev) < 0) + goto out; ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM); out: