From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752288AbeCTCuh (ORCPT ); Mon, 19 Mar 2018 22:50:37 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:35646 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752201AbeCTCu1 (ORCPT ); Mon, 19 Mar 2018 22:50:27 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4727061112 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: linux-scsi@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , QLogic-Storage-Upstream@qlogic.com, "James E.J. Bottomley" , "Martin K. Petersen" , linux-kernel@vger.kernel.org Subject: [PATCH v4 6/7] scsi: bnx2i: Eliminate duplicate barriers on weakly-ordered archs Date: Mon, 19 Mar 2018 22:50:06 -0400 Message-Id: <1521514207-10695-7-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521514207-10695-1-git-send-email-okaya@codeaurora.org> References: <1521514207-10695-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Code includes barrier() 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/bnx2i/bnx2i_hwi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c index 8f03a86..075735b 100644 --- a/drivers/scsi/bnx2i/bnx2i_hwi.c +++ b/drivers/scsi/bnx2i/bnx2i_hwi.c @@ -278,7 +278,7 @@ static void bnx2i_ring_sq_dbell(struct bnx2i_conn *bnx2i_conn, int count) sq_db->prod_idx = ep->qp.sq_prod_idx; bnx2i_ring_577xx_doorbell(bnx2i_conn); } else - writew(count, ep->qp.ctx_base + CNIC_SEND_DOORBELL); + writew_relaxed(count, ep->qp.ctx_base + CNIC_SEND_DOORBELL); mmiowb(); /* flush posted PCI writes */ } -- 2.7.4