Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760734AbZCYSFF (ORCPT ); Wed, 25 Mar 2009 14:05:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753840AbZCYSEy (ORCPT ); Wed, 25 Mar 2009 14:04:54 -0400 Received: from casper.infradead.org ([85.118.1.10]:54584 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753489AbZCYSEx (ORCPT ); Wed, 25 Mar 2009 14:04:53 -0400 Subject: Re: 2.6.29: can't resume from suspend with DMAR (intel iommu) enabled From: David Woodhouse To: Ingo Molnar Cc: Andrew Lutomirski , Jesse Barnes , Kyle McMartin , Fenghua Yu , Suresh Siddha , Yinghai Lu , Mark Gross , LKML In-Reply-To: <20090325175908.GA25518@elte.hu> References: <20090324203259.GC26930@elte.hu> <1238003581.2085.53.camel@macbook.infradead.org> <20090325175908.GA25518@elte.hu> Content-Type: text/plain Date: Wed, 25 Mar 2009 18:03:48 +0000 Message-Id: <1238004228.2085.56.camel@macbook.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.24.5 (2.24.5-1.fc10) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1379 Lines: 31 On Wed, 2009-03-25 at 18:59 +0100, Ingo Molnar wrote: > > that's not easy - i use it right now :) > > That's another reason why warnings and non-panic() behavior are > better for developers too. Had it not crashed i could have sent you > my dmesg and i would not have turned off DMAR in the BIOS. > > Now it's turned off in my BIOS (first barrier) and i need to reboot > the kernel (second barrier) and i need to hack up a kernel in a > certain way to produce debug info (third barrier) - in the merge > window (fourth barrier ;-). Yeah, trusting BIOS monkeys for this was always going to be a bad plan. We should have just known how to set/read the damn hardware BARs -- the most likely explanation for this is that your BIOS is just lying to you about where it put the registers, I believe. I'd like to put in a basic sanity check when we first ioremap the (alleged) DMAR registers. Hopefully, the output I asked for will confirm that there's a simple way to do that... -- David Woodhouse Open Source Technology Centre David.Woodhouse@intel.com Intel Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/