From patchwork Wed Sep 2 10:13:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yaniv Gardi X-Patchwork-Id: 7110671 X-Patchwork-Delegate: agross@codeaurora.org Return-Path: X-Original-To: patchwork-linux-arm-msm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 85E0FBEEC1 for ; Wed, 2 Sep 2015 10:17:17 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B2FAA20636 for ; Wed, 2 Sep 2015 10:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A998720644 for ; Wed, 2 Sep 2015 10:17:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753609AbbIBKOE (ORCPT ); Wed, 2 Sep 2015 06:14:04 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:60948 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753987AbbIBKN6 (ORCPT ); Wed, 2 Sep 2015 06:13:58 -0400 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 3D085140E84; Wed, 2 Sep 2015 10:13:58 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 1A61C140E98; Wed, 2 Sep 2015 10:13:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from lx-ygardi.mea.qualcomm.com (unknown [185.23.60.4]) (using TLSv1.1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: ygardi@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id C6FA6140E84; Wed, 2 Sep 2015 10:13:53 +0000 (UTC) From: Yaniv Gardi To: robherring2@gmail.com, James.Bottomley@HansenPartnership.com, pebolle@tiscali.nl, hch@infradead.org Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-arm-msm@vger.kernel.org, santoshsy@gmail.com, linux-scsi-owner@vger.kernel.org, subhashj@codeaurora.org, ygardi@codeaurora.org, gbroner@codeaurora.org, draviv@codeaurora.org, Vinayak Holikatti , "James E.J. Bottomley" Subject: [PATCH v3 06/15] scsi: ufs: avoid exception event handler racing with PM callbacks Date: Wed, 2 Sep 2015 13:13:06 +0300 Message-Id: <1441188795-4600-7-git-send-email-ygardi@codeaurora.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1441188795-4600-1-git-send-email-ygardi@codeaurora.org> References: <1441188795-4600-1-git-send-email-ygardi@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If device raises the exception event in the response to the commands sent during the runtime/system PM callbacks, exception event handler might run in parallel with PM callbacks and may see unclocked register accesses. This change fixes this issue by not scheduling the exception event handler while PM callbacks are running. Signed-off-by: Subhash Jadavani Signed-off-by: Yaniv Gardi --- drivers/scsi/ufs/ufshcd.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 573a8cb..0e54183 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -3145,7 +3145,20 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) scsi_status = result & MASK_SCSI_STATUS; result = ufshcd_scsi_cmd_status(lrbp, scsi_status); - if (ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) + /* + * Currently we are only supporting BKOPs exception + * events hence we can ignore BKOPs exception event + * during power management callbacks. BKOPs exception + * event is not expected to be raised in runtime suspend + * callback as it allows the urgent bkops. + * During system suspend, we are anyway forcefully + * disabling the bkops and if urgent bkops is needed + * it will be enabled on system resume. Long term + * solution could be to abort the system suspend if + * UFS device needs urgent BKOPs. + */ + if (!hba->pm_op_in_progress && + ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) schedule_work(&hba->eeh_work); break; case UPIU_TRANSACTION_REJECT_UPIU: