Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755245Ab3JCTVp (ORCPT ); Thu, 3 Oct 2013 15:21:45 -0400 Received: from mail-ie0-f171.google.com ([209.85.223.171]:51913 "EHLO mail-ie0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754562Ab3JCTVn (ORCPT ); Thu, 3 Oct 2013 15:21:43 -0400 MIME-Version: 1.0 In-Reply-To: <20131003172142.GA20660@hmsreliant.think-freely.org> References: <1380300815-1864-1-git-send-email-nhorman@tuxdriver.com> <20131003172142.GA20660@hmsreliant.think-freely.org> From: Bjorn Helgaas Date: Thu, 3 Oct 2013 13:21:22 -0600 Message-ID: Subject: Re: [PATCH] iommu: Remove stack trace from broken irq remapping warning To: Neil Horman Cc: "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , Joerg Roedel , Andy Lutomirski , Konrad Rzeszutek Wilk , Sebastian Andrzej Siewior Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3330 Lines: 69 On Thu, Oct 3, 2013 at 11:21 AM, Neil Horman wrote: > On Fri, Sep 27, 2013 at 12:53:35PM -0400, Neil Horman wrote: >> The warning for the irq remapping broken check in intel_irq_remapping.c is >> pretty pointless. We need the warning, but we know where its comming from, the >> stack trace will always be the same, and it needlessly triggers things like >> Abrt. This changes the warning to just print a text warning about BIOS being >> broken, without the stack trace, then sets the appropriate taint bit. Since we >> automatically disable irq remapping, theres no need to contiue making Abrt jump >> at this problem >> >> Signed-off-by: Neil Horman >> CC: Joerg Roedel >> CC: Bjorn Helgaas >> CC: Andy Lutomirski >> CC: Konrad Rzeszutek Wilk >> CC: Sebastian Andrzej Siewior >> --- >> drivers/iommu/intel_irq_remapping.c | 13 +++++++------ >> 1 file changed, 7 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c >> index f71673d..b97d70b 100644 >> --- a/drivers/iommu/intel_irq_remapping.c >> +++ b/drivers/iommu/intel_irq_remapping.c >> @@ -525,12 +525,13 @@ static int __init intel_irq_remapping_supported(void) >> if (disable_irq_remap) >> return 0; >> if (irq_remap_broken) { >> - WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND, >> - "This system BIOS has enabled interrupt remapping\n" >> - "on a chipset that contains an erratum making that\n" >> - "feature unstable. To maintain system stability\n" >> - "interrupt remapping is being disabled. Please\n" >> - "contact your BIOS vendor for an update\n"); >> + printk(KERN_WARNING >> + "This system BIOS has enabled interrupt remapping\n" >> + "on a chipset that contains an erratum making that\n" >> + "feature unstable. To maintain system stability\n" >> + "interrupt remapping is being disabled. Please\n" >> + "contact your BIOS vendor for an update\n"); >> + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); >> disable_irq_remap = 1; >> return 0; >> } >> -- >> 1.8.3.1 >> >> > > Ping Bjorn, Jeorg, any thoughts here? This is in drivers/iommu, so I'd prefer that Joerg handle this. My opinion is that this patch does the right thing in dropping the backtrace and keeping the taint. I tend to agree with Andy that we should also consider a second patch that drops the taint, because this is basically just a quirk that avoids broken chipset functionality, but as far as I can tell, there's no reason to fear an undebuggable problem related to disabling interrupt remapping. We don't taint the kernel for other similar quirks, so I don't see why we should here. Bjorn -- 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/