From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 92203CA9ECE for ; Thu, 31 Oct 2019 22:55:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7008820862 for ; Thu, 31 Oct 2019 22:55:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728398AbfJaWzl (ORCPT ); Thu, 31 Oct 2019 18:55:41 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:32873 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728207AbfJaWzk (ORCPT ); Thu, 31 Oct 2019 18:55:40 -0400 Received: by mail-pl1-f194.google.com with SMTP id y8so3431645plk.0 for ; Thu, 31 Oct 2019 15:55:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=2sp5hWX8cM1VYWqXk5IDcMfjtFajr2AWpOWYZwhDLQo=; b=qByHe3zej3c2dOJndfsLepNGylh3h5NRUG9FcQYZ6m+CHPZN0F673/rgmrSH6O/elT dhoK/+CKYE3TLElwXAXMhN4k2UtpYRJ8R+50syzC+5aYWISDPEs2e/bl7ElDLvSIgfjc 9bqg8bPnWKWl6XcbxdMFNdwT/9i/hRJ4PVdmKpnJ9666WuBY7z3/ZUva4K1B44cNkJz6 Bbb3rWn7LaDueh+sIzm/5SiMe30AvJuv18IMna0wOyA5+nK6j8Aql/dvn4iBkZFbZelM 09nkCnpOktJEsGLdKfwxL3fXfq9so12fxxl2xA8xOuKzV0/8aASwdkgzABXdcL8fWzPc tzMw== X-Gm-Message-State: APjAAAUbUkvOTmfnJyuCxLZoRweMe5VrZopOdxYTr7j5gvaCYBH5N3sY cJ3GDLeG1yAGYCQNL+cRMKE= X-Google-Smtp-Source: APXvYqyhN3jgEeslL8qj4BgDolHUEgIqP9iEEgHrCXqhYznqsyu4iV40hCwP6A73eiCHUOaWpW95gA== X-Received: by 2002:a17:902:44d:: with SMTP id 71mr8668947ple.274.1572562540055; Thu, 31 Oct 2019 15:55:40 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id d139sm8391711pfd.162.2019.10.31.15.55.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2019 15:55:39 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-scsi@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Gilad Broner , Yaniv Gardi , Subhash Jadavani , Stanley Chu , Avri Altman , Tomas Winkler Subject: [PATCH 4/4] ufs: Remove superfluous memory barriers Date: Thu, 31 Oct 2019 15:55:28 -0700 Message-Id: <20191031225528.233895-5-bvanassche@acm.org> X-Mailer: git-send-email 2.24.0.rc0.303.g954a862665-goog In-Reply-To: <20191031225528.233895-1-bvanassche@acm.org> References: <20191031225528.233895-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Calling wmb() after having written to a doorbell slows down code and does not help to commit the doorbell write faster. Hence remove such wmb() calls. Cc: Gilad Broner Cc: Yaniv Gardi Cc: Subhash Jadavani Cc: Stanley Chu Cc: Avri Altman Cc: Tomas Winkler Signed-off-by: Bart Van Assche --- drivers/scsi/ufs/ufshcd.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 8c969fab5d92..ace929df7bab 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1864,8 +1864,6 @@ 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(); ufshcd_add_command_trace(hba, task_tag, "send"); } @@ -5598,8 +5596,6 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba, wmb(); ufshcd_writel(hba, 1 << free_slot, REG_UTP_TASK_REQ_DOOR_BELL); - /* Make sure that doorbell is committed immediately */ - wmb(); spin_unlock_irqrestore(host->host_lock, flags); -- 2.24.0.rc0.303.g954a862665-goog