From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8667 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752961Ab1EDNZx (ORCPT ); Wed, 4 May 2011 09:25:53 -0400 Date: Wed, 4 May 2011 15:26:03 +0200 From: Stanislaw Gruszka To: Kalle Valo Cc: linux-wireless@vger.kernel.org Subject: Re: iwlagn: crash when unloading the module Message-ID: <20110504132602.GA2183@redhat.com> (sfid-20110504_152557_712732_5E745274) References: <87iptsgk5y.fsf@purkki.adurom.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <87iptsgk5y.fsf@purkki.adurom.net> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, May 03, 2011 at 01:20:25PM +0300, Kalle Valo wrote: > I noticed today a crash when removing iwlagn module. I can see the > crash everytime on my lenovo x201 (x86 64bit, i5) with this wireless > chip: > > [ 19.484551] iwlagn 0000:02:00.0: Detected Intel(R) Centrino(R) > Ultimate-N 6300 AGN, REV=0x74 > > As I'm travelling I only have two bad quality screenshots and 40 MB > video of the crash :) From the stacktrace it looks that this is iommu > related: > > http://www.adurom.com/~kvalo/tmp/iwlagn/rmmod-iommu-crash/1.png > http://www.adurom.com/~kvalo/tmp/iwlagn/rmmod-iommu-crash/2.png > > This is a new laptop and most likely I haven't removed iwlagn module > before. So this shouldn't be a regression. We can not exclude iwlagn problem only triggered with intel iommu, because problem does not happen with other modules, or does it? Except test patch pointed by Johannes, I suggest turning on CONFIG_DMA_API_DEBUG and test with intel_iommu=on and intel_iommu=off. Stanislaw