From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Cooper Subject: Re: [PATCH RFC v2 0/4] MDIO bus timeout issues on Dreamplug Date: Thu, 24 Oct 2013 17:25:21 -0400 Message-ID: <20131024212521.GM24520@titan.lakedaemon.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-arm-kernel@lists.infradead.org, Thomas Petazzoni , netdev@vger.kernel.org, sebastian.hesselbarth@gmail.com To: Leigh Brown Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:37923 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752501Ab3JXVZ0 (ORCPT ); Thu, 24 Oct 2013 17:25:26 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Leigh, Thanks for getting the bottom of this! On Thu, Oct 24, 2013 at 07:09:30PM +0100, Leigh Brown wrote: > Thanks to the comment from Sebastian I did some more investigation and > discovered that almost everything about my analysis was wrong (woops). > The patch itself wasn't too bad though. > > In terms of timings, I don't believe the timeout was due to the SMI bus > taking too long to respond because when I have repeated my testing > (this time disabling interrupts whilst waiting), I have found that the > maximum time that my Dreamplug takes to respond was about 95us (and > 43us on the Mirabox, which polls). So I think the root cause of the > problem was that interrupt handler was interfering with the polling in > some way. > > I have therefore amended the first patch to use usleep_range to sleep > instead of busy wait as suggested by Sebastian, and set the timeout to > 1ms. I've tested this on both the Dreamplug and Mirabox and have seen > no timeouts at all. > > The second, third and fourth patches are pretty much the same as before. > > If I receive no comments who do I submit this to for inclusion? You can can use scripts/get_maintainer.pl for this. In this case, it spits out: "David S. Miller" (commit_signer:63/70=90%) Thomas Petazzoni (commit_signer:15/70=21%) Sebastian Hesselbarth (commit_signer:10/70=14%) Florian Fainelli (commit_signer:8/70=11%) Stephen Hemminger (commit_signer:6/70=9%) netdev@vger.kernel.org (open list:NETWORKING DRIVERS) linux-kernel@vger.kernel.org (open list) thx, Jason.