From patchwork Tue Dec 1 08:53:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 335887 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 3EFD6C64E7A for ; Tue, 1 Dec 2020 09:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0DA4206CA for ; Tue, 1 Dec 2020 09:03:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qE/C6atc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387859AbgLAJDB (ORCPT ); Tue, 1 Dec 2020 04:03:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:39970 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727770AbgLAJCv (ORCPT ); Tue, 1 Dec 2020 04:02:51 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 498CE206C1; Tue, 1 Dec 2020 09:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606813330; bh=QnqNeQ8YPPwrJ/IQ6gFGEOgIou9X5w4DbBWp2jUcZs4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qE/C6atcZcrIATHRfOF57LSu8ThQs19P2BtdkkceCBx5XXW4qTPHrqCX70Z7yZuTj LQqPxoGZ/YEUZ/vThMxIyQFmFIOPBjI5OqUvYEL+5vCw53UUssSb3c/slx4/Is3Jl6 uNDfjbGox7dCNtuOy0EympFIP16kHg+syscXLoYU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Can Guo , Stanley Chu , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.19 31/57] scsi: ufs: Fix race between shutdown and runtime resume flow Date: Tue, 1 Dec 2020 09:53:36 +0100 Message-Id: <20201201084650.657187665@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084647.751612010@linuxfoundation.org> References: <20201201084647.751612010@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stanley Chu [ Upstream commit e92643db514803c2c87d72caf5950b4c0a8faf4a ] If UFS host device is in runtime-suspended state while UFS shutdown callback is invoked, UFS device shall be resumed for register accesses. Currently only UFS local runtime resume function will be invoked to wake up the host. This is not enough because if someone triggers runtime resume from block layer, then race may happen between shutdown and runtime resume flow, and finally lead to unlocked register access. To fix this, in ufshcd_shutdown(), use pm_runtime_get_sync() instead of resuming UFS device by ufshcd_runtime_resume() "internally" to let runtime PM framework manage the whole resume flow. Link: https://lore.kernel.org/r/20201119062916.12931-1-stanley.chu@mediatek.com Fixes: 57d104c153d3 ("ufs: add UFS power management support") Reviewed-by: Can Guo Signed-off-by: Stanley Chu Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/ufs/ufshcd.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a63119c35fde8..7e4e6e982055e 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -7926,11 +7926,7 @@ 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; - } + pm_runtime_get_sync(hba->dev); ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM); out: