Re: 3.2rc1: bootup fails: DRHD: handling fault status reg 2

[Arnd Hannemann]

Am 15.11.2011 05:36, schrieb Chris Wright:
> * Arnd Hannemann (arnd@xxxxxxxxxx) wrote:
>> Am 14.11.2011 23:33, schrieb Arnd Hannemann:
>>> when trying to boot kernel 3.2rc1 on my thinkpad t510 I get an endless loop of errors:
>>>
>>>  DRHD: handling fault status reg 2
>>>  DMAR: [DMA Read] Request device [0d:00.0] fault addr fffff000
>>>  DMAR: [fault reason 02] Present bit in context entry is clear
>>>
>>> screenshot can be found here:
>>> http://arndnet.de/lkml/screenshot3.2rc1.jpg
>>>
>>> kernel 3.1.1 is booting up flawlessly.
>>
>> I must have inadvertently enabled CONFIG_INTEL_IOMMU_DEFAULT_ON in my config
>> for 3.2-rc1.
>>
>> With disabled CONFIG_INTEL_IOMMU_DEFAULT_ON my thinkpad boots up again.
>> Not sure if this is expected?
> 
> With CONFIG_INTEL_IOMMU_DEFAULT_ON=n, you have to manually enabled the
> IOMMU on the kernel commandline.  So, yes, disabling that and having
> your laptop boot is not surprising.  The Kconfig item changed names,
> and the default is yes, so you may have had CONFIG_DMAR_DEFAULT_ON=n,
> but this would not have propagated forward.
> 
> As for the endless loop of DMAR faults...sounds like the Ricoh
> cardbus/firewire issue where the firewire fucntion does DMA from
> function 0.  I thought this was quirked and fixed though.

In this case it seems to be
0d:00.0 SD Host controller: Ricoh Co Ltd MMC/SD Host Controller (rev 01)
(using sdhci-pci)
The Fireware function seems to be at a different address:
0d:00.3 FireWire (IEEE 1394): Ricoh Co Ltd FireWire Host Controller (rev 01) (prog-if 10 [OHCI])

Maybe another quirk is needed? Where does this need to be fixed?
I suppose sdhci-pci.ko is loaded much later on bootup.

Best regards
Arnd
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