Re: [PATCH kernel] powerpc/powernv/ioda2: Add devices only from buses which belong to PE

On 12.06.2015 [16:47:03 +1000], Gavin Shan wrote:

On Fri, Jun 12, 2015 at 04:19:17PM +1000, Alexey Kardashevskiy wrote:

quoted

The existing code puts all devices from a root PE to the same IOMMU group.
However it is a possible situation when subordinate buses belong to
separate PEs, in this case devices from these subordinate buses
should be added to lower level PE rather to the root PE.

This limits pnv_ioda_setup_bus_dma() invocation to only PEs which own
all subordinate buses.

Suggested-by: Gavin Shan <redacted>
Signed-off-by: Alexey Kardashevskiy <redacted>

Alexey, I think it's good candidate for stable.

Why? This commit message doesn't imply there is a serious bug just a
"possible" (does that mean theoretical?) situtation and the following:

quoted

This would be nice to have together with the DDW patchset.
This does not fix anything DDW patchset did, it fixes IOMMU
groups management which is essential for the whole feature to work.

implies it is both related and independent of DDW?

-Nish