On 7/6/2010 8:40 PM, David Woodhouse wrote:
> On Tue, 2010-07-06 at 17:51 -0700, Dan Williams wrote:
>> It should always trigger, and I have verified as much with the attached
>> replacement patch (by forcing the error on a working system), but we run
>> into a new problem.
>>
>> IOMMU: can't find DMAR for device 0000:00:0f.0
>> Allocating domain for 0000:00:0f.0 failed
>
> Yeah, we're actually doing the check in the wrong place. This should
> work better, I think.
>

Ok.

Chris this change will make the driver's dma mapping calls succeed which 
means we once again need to be prepared for the case where the engine's 
iommu is not configured correctly.  Attached is David's latest combined 
with the driver error handling from v1.  The expectation is that this 
reports the BIOS misconfiguration each boot and the driver fails cleanly 
if its transactions are blocked.

Thanks for going through these iterations.

--
Dan