From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753823Ab0CKVVo (ORCPT ); Thu, 11 Mar 2010 16:21:44 -0500 Received: from mail-wy0-f174.google.com ([74.125.82.174]:38131 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753645Ab0CKVVm (ORCPT ); Thu, 11 Mar 2010 16:21:42 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=SGk2lpXHA2ZbR6POh8vqEBwNO7xzyDbV7awKK21rrNIJNgaYS8rlBoaKAlCtlQHA5V 5RIRR+l0ZNQW+Kvw6iMfOMNUFGbTrvsRzTjWvLt+AkqR5KZDsPDQEPLWHmWCXEsHem8d 2yfMDIWFyR2D/4r1Q6A0tPHG9wl5gRsCd1kr4= Message-ID: <4B995EE1.1050609@warmcat.com> Date: Thu, 11 Mar 2010 21:21:37 +0000 From: Andy Green User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc14 Thunderbird/3.0.3 MIME-Version: 1.0 To: Stanislav Brabec CC: Eric Miao , dbaryshkov@gmail.com, Cyril Hrubis , arminlitzel@web.de, kernel list , Dirk@opfer-online.de, lenz@cs.wisc.edu, rpurdie@rpsys.net, linux-arm-kernel , Pavel Machek , thommycheck@gmail.com, zaurus-devel@www.linuxtogo.org, omegamoon@gmail.com Subject: Re: bit errors on spitz References: <20100305212708.GC21773@elf.ucw.cz> <20100308072858.GA29939@atrey.karlin.mff.cuni.cz> <20100308082530.GA1982@atrey.karlin.mff.cuni.cz> <4B98EF5D.5000609@warmcat.com> <1268322155.3990.114.camel@hammer.suse.cz> In-Reply-To: <1268322155.3990.114.camel@hammer.suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/11/10 15:42, Somebody in the thread at some point said: > Andy Green wrote: > >> I saw very similar failures for a long time on our iMX31 based device. >> Eventually I found a Freescale errata where the RAM inside the USB2 >> macrocell started to make single bit errors below 1.38V Vcore; ours was >> 1.4V at that time but dipped on CPU load. > > Good tip. It seems that nobody ported driver for the voltage control > chip ISL6271 from 2.4 kernel, and bootloader probably does not set > correct values. > > Datasheet: > http://www.penguin.cz/~utx/zaurus/datasheets/power/Xscale/ISL6271.pdf Unless there's more to it in the way the zaurus using it that regulator isn't programmable digitally. Reading about your CF Card WLAN related issues they suck down a good amount of power when their radio is up, I would definitely suggest monitoring with a 'scope the various rails (Vcore, RAM and whatever it is the CF Card is powered by) while putting it under load. -Andy