From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 27 Dec 2011 23:49:05 +0100 (CET) Received: from qmta14.emeryville.ca.mail.comcast.net ([76.96.27.212]:55467 "EHLO qmta14.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1903622Ab1L0WtB (ORCPT ); Tue, 27 Dec 2011 23:49:01 +0100 Received: from omta16.emeryville.ca.mail.comcast.net ([76.96.30.72]) by qmta14.emeryville.ca.mail.comcast.net with comcast id ENAh1i0041ZMdJ4AENon8B; Tue, 27 Dec 2011 22:48:47 +0000 Received: from [192.168.1.13] ([76.106.69.86]) by omta16.emeryville.ca.mail.comcast.net with comcast id ENZ51i00Q1rgsis8cNZ7gG; Tue, 27 Dec 2011 22:33:07 +0000 Message-ID: <4EFA4B40.8090502@gentoo.org> Date: Tue, 27 Dec 2011 17:48:32 -0500 From: Joshua Kinard User-Agent: Mozilla/5.0 (Windows NT 6.0; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: Stephen Hemminger CC: netdev@vger.kernel.org, Linux MIPS List Subject: Re: [PATCH] net: meth: Add set_rx_mode hook to fix ICMPv6 neighbor discovery References: <4EED3A3D.9080503@gentoo.org> <4EF95247.7000403@gentoo.org> <20111227103408.01aad10e@nehalam.linuxnetplumber.net> <4EFA38D5.1000602@gentoo.org> <20111227143441.30d2c42f@nehalam.linuxnetplumber.net> In-Reply-To: <20111227143441.30d2c42f@nehalam.linuxnetplumber.net> X-Enigmail-Version: 1.3.4 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-archive-position: 32203 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: kumba@gentoo.org Precedence: bulk X-list: linux-mips Return-Path: X-Keywords: X-UID: 20180 On 12/27/2011 17:34, Stephen Hemminger wrote: > On Tue, 27 Dec 2011 16:29:57 -0500 > Joshua Kinard wrote: > >> MIPS I/O registers are always memory-mapped, and to prevent the compiler >> from trying to over-optimize, volatile is used to make sure we always read a >> value from the hardware and not from some cached value. > > Almost every other network driver had memory mapped register. > The problem is volatile is that the compiler is stupid and wrong. > Using explicit barriers is preferred and ensures correct and fast > code. I am somewhat new to driver development, so I do not know all the tricks of the trade just yet. Do you have references to doing explicit barriers that I can look at? Might be worth trying on the RTC driver I have to get the hang of them. -- Joshua Kinard Gentoo/MIPS kumba@gentoo.org 4096R/D25D95E3 2011-03-28 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic