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

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

On 7/22/2010 2:39 PM, Chris Li wrote:
> On Wed, Jul 21, 2010 at 6:15 PM, Dan Williams<dan.j.williams@intel.com>  wrote:
>>
>> Here is v5 with the aforementioned change.
>
> One warning.
>
> CC      drivers/pci/intel-iommu.o
> drivers/pci/intel-iommu.c: In function ‘quirk_ioat_snb_local_iommu’:
> drivers/pci/intel-iommu.c:3037: warning: unused variable ‘i’

Oops, I'll clean that up.

> The dmesg looks good.
>
[..]
> dca service started, version 1.12.1
> ioatdma: Intel(R) QuickData Technology Driver 4.00
> ioatdma 0000:00:0f.0: can't derive routing for PCI INT A
> ioatdma 0000:00:0f.0: PCI INT A: no GSI
> ------------[ cut here ]------------
> WARNING: at drivers/pci/intel-iommu.c:3056
> quirk_ioat_snb_local_iommu+0xae/0xc7()
> Hardware name: MacPro3,1
> BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device
[..]
> ---[ end trace c7f418b83f8ca665 ]---
> Disabling lock debugging due to kernel taint
> ioatdma 0000:00:0f.0: setting latency timer to 64
>    alloc irq_desc for 57 on node -1
>    alloc kstat_irqs on node -1
> ioatdma 0000:00:0f.0: irq 57 for MSI/MSI-X
>    alloc irq_desc for 58 on node -1
>    alloc kstat_irqs on node -1
> ioatdma 0000:00:0f.0: irq 58 for MSI/MSI-X
>    alloc irq_desc for 59 on node -1
>    alloc kstat_irqs on node -1
> ioatdma 0000:00:0f.0: irq 59 for MSI/MSI-X
>    alloc irq_desc for 60 on node -1
>    alloc kstat_irqs on node -1
> ioatdma 0000:00:0f.0: irq 60 for MSI/MSI-X
>

Nice, and the driver was able to load normally.  Thanks for the all the 
testing!

David, I'll take this through my tree as a regression fix (since 2.6.32) 
if you have no objections.  Now that we are not hitting a driver load 
failure I think I'll add a WARN() to this init-fail path.  I doubt we 
would have flushed out this problem had the driver been discretely 
handling init failures since day one.

Regards,
Dan