From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756029Ab3A0OeF (ORCPT ); Sun, 27 Jan 2013 09:34:05 -0500 Received: from mail-ob0-f174.google.com ([209.85.214.174]:51600 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754965Ab3A0Od6 (ORCPT ); Sun, 27 Jan 2013 09:33:58 -0500 Message-ID: <51053AD2.8080805@gmail.com> Date: Sun, 27 Jan 2013 08:33:54 -0600 From: Nishanth Menon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Paolo Pisati CC: Mats Liljegren , Tony Lindgren , LKML , Steven Rostedt , Igor Grinberg , Russell King , Venkatraman S , linux-arm-kernel , linux-omap Subject: Re: [BUG] panda board locks up on boot References: <1359082886.21576.199.camel@gandalf.local.home> <51022FD2.8090101@compulab.co.il> <0247700D01F14443B9209F90AD938CC52409708C@sestoex09.enea.se> <20130127141254.GC5714@stinkpad> In-Reply-To: <20130127141254.GC5714@stinkpad> 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 01/27/2013 08:12 AM, Paolo Pisati wrote: > On Fri, Jan 25, 2013 at 08:43:15AM +0000, Mats Liljegren wrote: >> Hi Steven, >> >> Do you have CONFIG_CPU_FREQ enabled? As I posted earlier in linux-kernel forum ("Failed booting PandaBoard ES with Linux 3.8 RC4" two days ago) my PandaBoard ES hangs while booting with this option enabled. It works fine without it. I have not bisected it down to a single commit though. > > glad i'm not the only one who hit this problem: > > "3.8rc4+ and cpu_freq omap: hangs, oopses, etcetc" > > http://www.mail-archive.com/linux-omap@vger.kernel.org/msg83693.html > Support for TPS is not yet in mainline kernel. you may want to do: you could try running 'mw.w 0x4A31E05A 0x1' before bootm in u-boot -> This will hack the pad of panda ES pin mean for controlling TPS voltage register (again a kernel bug where the GPIO block setup by bootloader got reset). CPUfreq needs both voltage and frequency scaling to work and without support of the TPS voltage scaling on vdd_MPU, you are stuck at boot voltage, and just scaling frequency. with the not-enough boot voltage, moving to higher frequencies can/will result in unpredictable behavior. --- Regards, NM