From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758990Ab2CFKoD (ORCPT ); Tue, 6 Mar 2012 05:44:03 -0500 Received: from antcom.de ([188.40.178.216]:44082 "EHLO chuck.antcom.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758905Ab2CFKoA (ORCPT ); Tue, 6 Mar 2012 05:44:00 -0500 Message-ID: <4F55EA6D.3070602@antcom.de> Date: Tue, 06 Mar 2012 11:43:57 +0100 From: Roland Stigge Organization: ANTCOM IT Research & Development User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:8.0) Gecko/20120216 Icedove/8.0 MIME-Version: 1.0 To: Ben Hutchings CC: davem@davemloft.net, jeffrey.t.kirsher@intel.com, alexander.h.duyck@intel.com, eilong@broadcom.com, ian.campbell@citrix.com, netdev@vger.kernel.org, w.sang@pengutronix.de, linux-kernel@vger.kernel.org, kevin.wells@nxp.com, linux-arm-kernel@lists.infradead.org, arnd@arndb.de, baruch@tkos.co.il, joe@perches.com Subject: Re: [PATCH v4] lpc32xx: Added ethernet driver: smp_wmb() References: <1330983641-32622-1-git-send-email-stigge@antcom.de> <1330987524.2538.61.camel@bwh-desktop> In-Reply-To: <1330987524.2538.61.camel@bwh-desktop> X-Enigmail-Version: 1.3.4 OpenPGP: url=subkeys.pgp.net Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2012 11:45 PM, Ben Hutchings wrote: >> + /* Clear and enable interrupts */ >> + writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base)); >> + lpc_eth_enable_int(pldat->net_base); >> + >> + /* Get the next TX buffer output index */ >> + pldat->num_used_tx_buffs = 0; >> + pldat->last_tx_idx = >> + readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base)); > > Doesn't this need to be done *before* enabling interrupts? Also, I > think you need an smp_wmb() so that the interrupt handler is guaranteed > to see all these writes. Do you mean _one_ smp_wmb() directly after lpc_eth_enable_int() (which I'm moving behind the above code? Note that there is no SMP in LPCs and NXP is not planning to build one AFAIK. However, I'm fine with including smp_wmb() anyway for completeness. Thanks in advance, Roland