From patchwork Thu Jan 23 07:25:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Can Guo X-Patchwork-Id: 11346885 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 A81AC6C1 for ; Thu, 23 Jan 2020 07:26:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 858A524673 for ; Thu, 23 Jan 2020 07:26:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="EwPG0fVx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726143AbgAWH0D (ORCPT ); Thu, 23 Jan 2020 02:26:03 -0500 Received: from mail25.static.mailgun.info ([104.130.122.25]:15242 "EHLO mail25.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbgAWH0D (ORCPT ); Thu, 23 Jan 2020 02:26:03 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1579764362; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=9S0QIlbYmQAb+fbkT7yD3PV4Zf5YseEdwAjssYu+PQ8=; b=EwPG0fVxtIYH3FU+NobMSIxKzRsNiFh6FI/gYG9UCw+2bPhHP0FrPUod+q52vBsNqILTAsIp PYDX+yIIaNeuMLEAU7MKSpqOJA7kGpBcVF2qzLSMxdg9ZxGrmsuQnZnIiGwl3ZsGlYWvx6se 76Fna/zDopZHctJpCZRmf6hiG18= X-Mailgun-Sending-Ip: 104.130.122.25 X-Mailgun-Sid: WyJlNmU5NiIsICJsaW51eC1zY3NpQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5e294a8a.7fd2376666f8-smtp-out-n01; Thu, 23 Jan 2020 07:26:02 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1B3C1C447A5; Thu, 23 Jan 2020 07:26:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.0 Received: from pacamara-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 666D0C43383; Thu, 23 Jan 2020 07:26:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 666D0C43383 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=cang@codeaurora.org From: Can Guo To: asutoshd@codeaurora.org, nguyenb@codeaurora.org, hongwus@codeaurora.org, rnayak@codeaurora.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com, cang@codeaurora.org Cc: Sayali Lokhande , Alim Akhtar , Avri Altman , Pedro Sousa , "James E.J. Bottomley" , "Martin K. Petersen" , Stanley Chu , Bean Huo , Venkat Gopalakrishnan , Tomas Winkler , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v4 1/8] scsi: ufs: Flush exception event before suspend Date: Wed, 22 Jan 2020 23:25:42 -0800 Message-Id: <1579764349-15578-2-git-send-email-cang@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1579764349-15578-1-git-send-email-cang@codeaurora.org> References: <1579764349-15578-1-git-send-email-cang@codeaurora.org> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Sayali Lokhande Exception event can be raised by the device when system suspend is in progress. This will result in unclocked register access in exception event handler as clocks will be turned off during suspend. This change makes sure to flush exception event handler work in suspend before disabling clocks to avoid unclocked register access issue. Signed-off-by: Sayali Lokhande Signed-off-by: Asutosh Das Signed-off-by: Can Guo --- drivers/scsi/ufs/ufshcd.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 1201578..c2de29f 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -4760,8 +4760,15 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev) * UFS device needs urgent BKOPs. */ if (!hba->pm_op_in_progress && - ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) - schedule_work(&hba->eeh_work); + ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) { + /* + * Prevent suspend once eeh_work is scheduled + * to avoid deadlock between ufshcd_suspend + * and exception event handler. + */ + if (schedule_work(&hba->eeh_work)) + pm_runtime_get_noresume(hba->dev); + } break; case UPIU_TRANSACTION_REJECT_UPIU: /* TODO: handle Reject UPIU Response */ @@ -5215,7 +5222,14 @@ static void ufshcd_exception_event_handler(struct work_struct *work) out: scsi_unblock_requests(hba->host); - pm_runtime_put_sync(hba->dev); + /* + * pm_runtime_get_noresume is called while scheduling + * eeh_work to avoid suspend racing with exception work. + * Hence decrement usage counter using pm_runtime_put_noidle + * to allow suspend on completion of exception event handler. + */ + pm_runtime_put_noidle(hba->dev); + pm_runtime_put(hba->dev); return; } @@ -7901,6 +7915,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) goto enable_gating; } + flush_work(&hba->eeh_work); ret = ufshcd_link_state_transition(hba, req_link_state, 1); if (ret) goto set_dev_active;