From patchwork Tue Apr 28 19:07:39 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Dykstra X-Patchwork-Id: 26585 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@bilbo.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id CD9B8B7063 for ; Wed, 29 Apr 2009 05:32:51 +1000 (EST) Received: by ozlabs.org (Postfix) id BF8E6DDEF3; Wed, 29 Apr 2009 05:32:51 +1000 (EST) Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 4475BDDEF2 for ; Wed, 29 Apr 2009 05:32:51 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756134AbZD1Tcm (ORCPT ); Tue, 28 Apr 2009 15:32:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754912AbZD1Tcl (ORCPT ); Tue, 28 Apr 2009 15:32:41 -0400 Received: from mail-qy0-f128.google.com ([209.85.221.128]:33514 "EHLO mail-qy0-f128.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753585AbZD1Tck (ORCPT ); Tue, 28 Apr 2009 15:32:40 -0400 X-Greylist: delayed 1498 seconds by postgrey-1.27 at vger.kernel.org; Tue, 28 Apr 2009 15:32:40 EDT Received: by qyk34 with SMTP id 34so336714qyk.33 for ; Tue, 28 Apr 2009 12:32:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:subject:from:to:content-type :date:message-id:mime-version:x-mailer:content-transfer-encoding; bh=tiBzFa6Cvdquy48b5ArLGNZTPjEY3SIWpUUeAdVKHbE=; b=aY6VNUUZGPX0l0qhYpMj2fVST6U3j59+fUQ7lu6LrmJSvzxJZvizu76HO/ZZ0lQ2Wz GmgusnUAWzoPmMPdeJr2BuIwuTmONeO+ks6tvdBu/xP30dAqTmTmEk60spUEK5r8EnBi CN6VxuQ4XazV4wi+ANAUI2dTsudM0pjB6Qaew= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:content-type:date:message-id:mime-version:x-mailer :content-transfer-encoding; b=DPW4vrkkRSIwnPbGICZfCNxwTqkw8CmMjP2TVxiJnK0Rl8QOoOWNC/vLj2VIydGzJy qW4lHk52w9fN7PMb0givMrpBTHCr9pWnkbdky93MpAtLGddE4j60sAp15Nh+58ng3ayl 7bqezlwluZtWb1EmOQdD5budBp7c03woVdQRY= Received: by 10.229.96.13 with SMTP id f13mr4130426qcn.36.1240945661574; Tue, 28 Apr 2009 12:07:41 -0700 (PDT) Received: from ?192.168.221.201? (c-24-118-80-156.hsd1.mn.comcast.net [24.118.80.156]) by mx.google.com with ESMTPS id 9sm364889ywf.9.2009.04.28.12.07.40 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 28 Apr 2009 12:07:40 -0700 (PDT) Subject: [PATCH net-next-2.6] pcnet32: Remove pointless memory barriers From: John Dykstra To: netdev , Don Fry Date: Tue, 28 Apr 2009 19:07:39 +0000 Message-Id: <1240945659.8819.9.camel@Maple> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org These two memory barriers in performance-critical paths are not needed on x86. Even if some other architecture does buffer PCI I/O space writes, the existing memory-mapped I/O barriers are unlikely to be what is needed. Signed-off-by: John Dykstra --- drivers/net/pcnet32.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/pcnet32.c b/drivers/net/pcnet32.c index e5e8c59..1c35e1d 100644 --- a/drivers/net/pcnet32.c +++ b/drivers/net/pcnet32.c @@ -1405,7 +1405,7 @@ static int pcnet32_poll(struct napi_struct *napi, int budget) /* Set interrupt enable. */ lp->a.write_csr(ioaddr, CSR0, CSR0_INTEN); - mmiowb(); + spin_unlock_irqrestore(&lp->lock, flags); } return work_done; @@ -2597,7 +2597,7 @@ pcnet32_interrupt(int irq, void *dev_id) val = lp->a.read_csr(ioaddr, CSR3); val |= 0x5f00; lp->a.write_csr(ioaddr, CSR3, val); - mmiowb(); + __napi_schedule(&lp->napi); break; }