From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joshua Kinard Subject: Re: [PATCH] net: meth: Add set_rx_mode hook to fix ICMPv6 neighbor discovery Date: Tue, 27 Dec 2011 16:29:57 -0500 Message-ID: <4EFA38D5.1000602@gentoo.org> References: <4EED3A3D.9080503@gentoo.org> <4EF95247.7000403@gentoo.org> <20111227103408.01aad10e@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Linux MIPS List To: Stephen Hemminger Return-path: Received: from qmta12.emeryville.ca.mail.comcast.net ([76.96.27.227]:49945 "EHLO qmta12.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751342Ab1L0VaN (ORCPT ); Tue, 27 Dec 2011 16:30:13 -0500 In-Reply-To: <20111227103408.01aad10e@nehalam.linuxnetplumber.net> Sender: netdev-owner@vger.kernel.org List-ID: On 12/27/2011 13:34, Stephen Hemminger wrote: > On Tue, 27 Dec 2011 00:06:15 -0500 > Joshua Kinard wrote: > >> @@ -95,7 +95,7 @@ struct mace_video { >> * Ethernet interface >> */ >> struct mace_ethernet { >> - volatile unsigned long mac_ctrl; >> + volatile u64 mac_ctrl; >> volatile unsigned long int_stat; >> volatile unsigned long dma_ctrl; >> volatile unsigned long timer; > > > This device driver writer needs to read: > Documentation/volatile-considered-harmful.txt 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. See MIPS Run (2nd Ed), pp 307, section 10.5.2 highlights an example of this, which is viewable here: http://books.google.com/books?id=kk8G2gK4Tw8C&pg=PA307&lpg=PA308#v=onepage&q&f=false But other than that, yeah, this driver needs to pretty much be stripped down to the nuts and bolts and re-written. Maybe something to tackle in the future. I still haven't gotten around to submitting the RTC driver for O2's (that I re-wrote from a patch sent into LKML years ago) upstream yet. -- 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