On Thu, Oct 3, 2013 at 11:21 AM, Neil Horman <nhorman@xxxxxxxxxxxxx> 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 <nhorman@xxxxxxxxxxxxx>
>> CC: Joerg Roedel <joro@xxxxxxxxxx>
>> CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>> CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
>> CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
>> CC: Sebastian Andrzej Siewior <sebastian@xxxxxxxxxxxxx>
>> ---
>> 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
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