From patchwork Wed Oct 28 13:13:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yaniv Gardi X-Patchwork-Id: 7510961 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 56AB19F327 for ; Wed, 28 Oct 2015 13:18:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 806B1205E9 for ; Wed, 28 Oct 2015 13:18:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D8C1205DB for ; Wed, 28 Oct 2015 13:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965785AbbJ1NSV (ORCPT ); Wed, 28 Oct 2015 09:18:21 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:45720 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965924AbbJ1NOj (ORCPT ); Wed, 28 Oct 2015 09:14:39 -0400 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 393CE14095C; Wed, 28 Oct 2015 13:14:38 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 28A1D140959; Wed, 28 Oct 2015 13:14:38 +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, 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 7A98B14093F; Wed, 28 Oct 2015 13:14:34 +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 v6 06/15] scsi: ufs: avoid exception event handler racing with PM callbacks Date: Wed, 28 Oct 2015 15:13:56 +0200 Message-Id: <1446038045-17102-7-git-send-email-ygardi@codeaurora.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1446038045-17102-1-git-send-email-ygardi@codeaurora.org> References: <1446038045-17102-1-git-send-email-ygardi@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@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. Reviewed-by: Gilad Broner Reviewed-by: Dolev Raviv 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: