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[209.132.180.67]) by mx.google.com with ESMTP id 59-v6si1225063plc.0.2018.03.13.20.23.01; Tue, 13 Mar 2018 20:23:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=Q0ziA0tu; dkim=pass header.i=@codeaurora.org header.s=default header.b=cDif6xXc; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933540AbeCNDVs (ORCPT + 99 others); Tue, 13 Mar 2018 23:21:48 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43412 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933404AbeCNDUm (ORCPT ); Tue, 13 Mar 2018 23:20:42 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 2DBED60F6B; Wed, 14 Mar 2018 03:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1520997642; bh=ZdSDtqqrrxUcevrOlVFc+bc1wDyZ/NSgGMrKeIBB2So=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q0ziA0tuUeEZTl6CZnahoMoO0wox+6s6X8sryEH7jqeCXbsDgNnpEISqo3+tX9Z+V CXKkjdOe3s0LZV2TbB7q0ljOeiGzfcLfd0ycPVS3crfvGm8bfviA6KnCH75pur+s0t AwyAJcqn72TUnnmZwW/iMYPp6tzixlXrZo00cFWw= X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=2.0 tests=ALL_TRUSTED,BAYES_00, DKIM_SIGNED,T_DKIM_INVALID autolearn=no autolearn_force=no version=3.4.0 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 9418060A05; Wed, 14 Mar 2018 03:20:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1520997641; bh=ZdSDtqqrrxUcevrOlVFc+bc1wDyZ/NSgGMrKeIBB2So=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cDif6xXc50IEpf4M1vas649eWyDa7+sUbqkp21EYBFw+FotJjTnwmcHox+Ei+HjGY WT36GzIrL8dMy6KKivJwXE78n7jHay4nTAgYErjIdUAbVBuuSURk43RvjjSZgtsLj6 pHJt4L63e3LJk64F5RRo1NAI+wmtE0hFDWsA+WE4= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 9418060A05 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 5/7] igb: eliminate duplicate barriers on weakly-ordered archs Date: Tue, 13 Mar 2018 23:20:26 -0400 Message-Id: <1520997629-17361-5-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 Precedence: bulk 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/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index b88fae7..ba8ccb5 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -8072,7 +8072,7 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16 cleaned_count) * such as IA-64). */ wmb(); - writel(i, rx_ring->tail); + writel_relaxed(i, rx_ring->tail); } } -- 2.7.4