From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933516AbeCNDVQ (ORCPT ); Tue, 13 Mar 2018 23:21:16 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43588 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933429AbeCNDUp (ORCPT ); Tue, 13 Mar 2018 23:20:45 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4514460867 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 , Jeff Kirsher , intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH 6/7] e1000: eliminate duplicate barriers on weakly-ordered archs Date: Tue, 13 Mar 2018 23:20:27 -0400 Message-Id: <1520997629-17361-6-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1520997629-17361-1-git-send-email-okaya@codeaurora.org> References: <1520997629-17361-1-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 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/net/ethernet/intel/e1000/e1000_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 3dd4aeb..e0e583a 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -4573,7 +4573,7 @@ e1000_alloc_jumbo_rx_buffers(struct e1000_adapter *adapter, * such as IA-64). */ wmb(); - writel(i, adapter->hw.hw_addr + rx_ring->rdt); + writel_relaxed(i, adapter->hw.hw_addr + rx_ring->rdt); } } @@ -4688,7 +4688,7 @@ static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter, * such as IA-64). */ wmb(); - writel(i, hw->hw_addr + rx_ring->rdt); + writel_relaxed(i, hw->hw_addr + rx_ring->rdt); } } -- 2.7.4