Re: BUG in drivers/dma/ioat/dma_v2.c:314

[Dan Williams <dan.j.williams@intel.com>]

On 7/6/2010 5:51 PM, Chris Li wrote:
> On Tue, Jul 6, 2010 at 5:51 PM, Dan Williams<dan.j.williams@intel.com>  wrote:
>> No, it should be PCI_DEVICE_ID_INTEL_IOAT_SNB (0x402f) for the dma
>> engine at 00:0f.0 .  PCI_DEVICE_ID_INTEL_ESB2_0 is the LPC controller at
>> 00:1f.0,
>>
>>> That seems to be the reason preventing the warning to be print out. I am not
>>> sure the warning should be always print out. Just curious why it did
>>> not trigger.
>>
>> 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.  dma_pool_alloc() assumes that any dma_mapping error
>> is transient.  Do we need a new type of dma_mapping_error() that
>> indicates permanent failure versus ENOMEM?  The driver can handle the
>> allocation failure, but it never gets the chance.
>
> Should I test your V2 patch instead?
>

It would confirm that we are catching the BIOS misconfiguration, but 
your system will get stuck in this loop.  So just make sure you can get 
back to a working config, which it sounds like you can.

--
Dan