From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753144AbeCUS4l (ORCPT ); Wed, 21 Mar 2018 14:56:41 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:59172 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057AbeCUS4b (ORCPT ); Wed, 21 Mar 2018 14:56:31 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org B8A9860FA8 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: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH REPOST v4 6/7] ixgbevf: eliminate duplicate barriers on weakly-ordered archs Date: Wed, 21 Mar 2018 14:56:10 -0400 Message-Id: <1521658572-26354-7-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1521658572-26354-1-git-send-email-okaya@codeaurora.org> References: <1521658572-26354-1-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() in multiple places. 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 Reviewed-by: Alexander Duyck --- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index 6bf778a..774b2a6 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -659,7 +659,7 @@ static void ixgbevf_alloc_rx_buffers(struct ixgbevf_ring *rx_ring, * such as IA-64). */ wmb(); - writel(i, rx_ring->tail); + writel_relaxed(i, rx_ring->tail); } } @@ -3644,7 +3644,7 @@ static void ixgbevf_tx_map(struct ixgbevf_ring *tx_ring, tx_ring->next_to_use = i; /* notify HW of packet */ - writel(i, tx_ring->tail); + writel_relaxed(i, tx_ring->tail); return; dma_error: -- 2.7.4