From patchwork Fri Aug 21 22:09:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yaniv Gardi X-Patchwork-Id: 7054311 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 B96019F2B4 for ; Fri, 21 Aug 2015 22:11:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DC549204B5 for ; Fri, 21 Aug 2015 22:11:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 027D3204AD for ; Fri, 21 Aug 2015 22:11:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753323AbbHUWLB (ORCPT ); Fri, 21 Aug 2015 18:11:01 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:37542 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753274AbbHUWK7 (ORCPT ); Fri, 21 Aug 2015 18:10:59 -0400 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 4E529140720; Fri, 21 Aug 2015 22:10:54 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 35546140722; Fri, 21 Aug 2015 22:10:54 +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=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham 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 4AD9B14071E; Fri, 21 Aug 2015 22:10:50 +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 v1 14/15] scsi: ufs: commit descriptors before setting the doorbell Date: Sat, 22 Aug 2015 01:09:48 +0300 Message-Id: <1440194989-28835-15-git-send-email-ygardi@codeaurora.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1440194989-28835-1-git-send-email-ygardi@codeaurora.org> References: <1440194989-28835-1-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 Add a write memory barrier to make sure descriptors prepared are actually written to memory before ringing the doorbell. We have also added the write memory barrier after ringing the doorbell register so that controller sees the new request immediately. Signed-off-by: Yaniv Gardi --- drivers/scsi/ufs/ufshcd.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index fef0660..876148b 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -833,6 +833,8 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag) ufshcd_clk_scaling_start_busy(hba); __set_bit(task_tag, &hba->outstanding_reqs); ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL); + /* Make sure that doorbell is committed immediately */ + wmb(); } /** @@ -1418,6 +1420,8 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) goto out; } + /* Make sure descriptors are ready before ringing the doorbell */ + wmb(); /* issue command to the controller */ spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_send_command(hba, tag); @@ -1627,6 +1631,8 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, hba->dev_cmd.complete = &wait; + /* Make sure descriptors are ready before ringing the doorbell */ + wmb(); spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_send_command(hba, tag); spin_unlock_irqrestore(hba->host->host_lock, flags);