From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: linux-next - multi-omap image fails to boot on omap3/4 Date: Fri, 22 Oct 2010 14:38:43 -0700 Message-ID: <20101022213843.GJ17595@atomide.com> References: <20101019182149.GC3038@atomide.com> <20101019225726.GE3038@atomide.com> <20101019233204.GA30991@atomide.com> <20101021161545.GC3616@atomide.com> <8fb818d83ad3cb8e8e979e9b4ac52736@mail.gmail.com> <20101022185254.GG17595@atomide.com> <4CC1F0FF.4000701@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:64488 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032Ab0JVVir (ORCPT ); Fri, 22 Oct 2010 17:38:47 -0400 Content-Disposition: inline In-Reply-To: <4CC1F0FF.4000701@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Anand Gadiyar Cc: linux-omap@vger.kernel.org * Anand Gadiyar [101022 13:07]: > On 10/22/2010 2:52 PM, Tony Lindgren wrote: > > > >Yeah, it's an alignment issue that's why it sometimes works depending > >on the Kconfig options selected.. > > > >For rererence, posted a fix for that at: > > > >https://patchwork.kernel.org/patch/276161/ > > The patch seems to work - thanks! Just curious, how do you go about > debugging an issue like this? Well it was a bit tricky to find out as random changes to .config would make it work. Found the breaking patch with git bisect, but could not see anything wrong with it. Then thought it somehow misbehaves with CONFIG_SMP_ON_UP, but some printhex8 debugging showed that it happens even earlier. Then went back few lines in the boot to narrow it down, but finally had to step through it with jtag to see that the address loaded into r5 was not aligned. Tony