From patchwork Fri Mar 16 16:16:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 10289055 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 037E86063D for ; Fri, 16 Mar 2018 16:23:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E80FC28FC9 for ; Fri, 16 Mar 2018 16:23:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DBE1B28FC7; Fri, 16 Mar 2018 16:23:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 96FD128FC7 for ; Fri, 16 Mar 2018 16:23:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754730AbeCPQRF (ORCPT ); Fri, 16 Mar 2018 12:17:05 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:39480 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754538AbeCPQRB (ORCPT ); Fri, 16 Mar 2018 12:17:01 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 07BF560592; Fri, 16 Mar 2018 16:17:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521217021; bh=W9/yviHskqvwFPloVpoKaCcmJwlqdPqG2IWrksKoXY0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eNcGtAWWetgUcdm6nYeQ8/uGK8ak3qWgPq3tWk5p6zagUMIWYy5S78Yk5WgtBgw9K 1EIQ1aeb8Zx3t01hRxhfOl7u6t//i6hHLvpuX0WBe5RQk9xxlOAGfZThFRB43ik9Cy a3YyRwpC6fJSvNh2533XUU8hHyb/nOYr38dz58/k= Received: from drakthul.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: okaya@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 8B4C460390; Fri, 16 Mar 2018 16:16:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1521217020; bh=W9/yviHskqvwFPloVpoKaCcmJwlqdPqG2IWrksKoXY0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XpLbgktcx7q0nf24IFOwQFpwfmHt089eALpvpOCp50TvDOeOQRJHCSBOfAKk2lz6I iUyi96Q/YzlziahdQWIjTmHH5rk+aLCq4o98hypvtcZ8TR/VpCMSYD948fpCjfPVvl mj91nAkYOgTE+jrrSZQVqgJuX/Q32dC+pxck/EYI= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 8B4C460390 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org From: Sinan Kaya To: netdev@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , Don Brace , "James E.J. Bottomley" , "Martin K. Petersen" , esc.storagedev@microsemi.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 08/18] scsi: hpsa: Eliminate duplicate barriers on weakly-ordered archs Date: Fri, 16 Mar 2018 12:16:21 -0400 Message-Id: <1521216991-28706-9-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521216991-28706-1-git-send-email-okaya@codeaurora.org> References: <1521216991-28706-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 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 Code includes wmb() followed by writel(). writel() already has a barrier on some architectures like arm64. This ends up CPU observing two barriers back to back before executing the register write. Since code already has an explicit barrier call, changing writel() to writel_relaxed(). Signed-off-by: Sinan Kaya --- drivers/scsi/hpsa.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h index 018f980..c7d7e6a 100644 --- a/drivers/scsi/hpsa.h +++ b/drivers/scsi/hpsa.h @@ -599,7 +599,7 @@ static unsigned long SA5_ioaccel_mode1_completed(struct ctlr_info *h, u8 q) * but with current driver design this is easiest. */ wmb(); - writel((q << 24) | rq->current_entry, h->vaddr + + writel_relaxed((q << 24) | rq->current_entry, h->vaddr + IOACCEL_MODE1_CONSUMER_INDEX); atomic_dec(&h->commands_outstanding); }