> OK, nailed it.
>
> It's commit 5f08e46b621a769e52a9545a23ab1d5fb2aec1d4 aka "atl1:
> disable broken 64-bit DMA".
>
> With this commit in tree, I can reproduce either
> a) kmalloc-2048 corruption after initscripts shutdown eth0
>
http://marc.info/?l=linux-kernel&m=120820360221261&w=2
>
> b) or oopses at filp_close() first reported long ago
> (sorry, can't find that email)
>
> c) or hard hang after initscripts shutdown eth0 with even SysRq not
> working.
http://marc.info/?l=linux-kernel&m=120795046008115&w=2
>
> I have two boxes one with atl1, 4G RAM with 2G remapped after 4G
> boundary, another with r8169 connected with just ethernet cable. NICs
> agree on 1Gbps speed.
>
> So, it's enough to scp 200 MB git archive and immediately start
> rebooting sequence for horrors described above to appear. It's not
> 100% reproducible but more like 90%.