Re: igb driver can cause cache invalidation of non-owned memory?

[Nikita Yushchenko]

>> All the data has been synced
> 
> Non-synced data is write done by CPU executing upper layers of network stack,

Upper layers shall never get area that is still dma_map()ed and will be
dma_unmap()ed in future.  But with igb, this is exactly what happens.