From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: 8139cp: set ring address before enabling receiver Date: Wed, 21 Nov 2012 13:12:02 -0500 Message-ID: <50AD1972.5080403@pobox.com> References: <20120602235020.2C0A57C006C@ra.kernel.org> <1353517042.26346.130.camel@shinybook.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Jason Wang , "David S. Miller" , netdev@vger.kernel.org To: David Woodhouse Return-path: Received: from mail-vc0-f174.google.com ([209.85.220.174]:53168 "EHLO mail-vc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755353Ab2KUSMJ (ORCPT ); Wed, 21 Nov 2012 13:12:09 -0500 Received: by mail-vc0-f174.google.com with SMTP id m18so3828498vcm.19 for ; Wed, 21 Nov 2012 10:12:08 -0800 (PST) In-Reply-To: <1353517042.26346.130.camel@shinybook.infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: On 11/21/2012 11:57 AM, David Woodhouse wrote: > On Sat, 2012-06-02 at 23:50 +0000, Linux Kernel Mailing List wrote: >> Gitweb: http://git.kernel.org/linus/;a=commit;h=b01af4579ec41f48e9b9c774e70bd6474ad210db >> Commit: b01af4579ec41f48e9b9c774e70bd6474ad210db >> Parent: 20e2a86485967c385d7c7befc1646e4d1d39362e >> Author: Jason Wang >> AuthorDate: Thu May 31 18:19:39 2012 +0000 >> Committer: David S. Miller >> CommitDate: Fri Jun 1 14:22:11 2012 -0400 >> >> 8139cp: set ring address before enabling receiver >> >> Currently, we enable the receiver before setting the ring address which could >> lead the card DMA into unexpected areas. Solving this by set the ring address >> before enabling the receiver. >> >> btw. I find and test this in qemu as I didn't have a 8139cp card in hand. please >> review it carefully. What sticks out at me from the commit message? It was not tested on the famously quirky 8139 hardware at all. While I have not looked at the 8139C+ data sheet in a while, sometimes the hardware _did_ have a strange init order. As this works in a simulator but fails on real hardware, it seems like an obvious regression caused by an untested [on read hardware] patch. Jeff