On Mon, Mar 13, 2017 at 09:47:57AM +0000, James Hogan wrote: > > > > Note that the corruption is different across reboots, both in the size > > of the corruption and the location. I saw 1900~ and 1400~ byte > > sequences corrupted on separate occasions, which don't correspond to > > the system's 16kB page size. > > > > I've tested kernels from v3.19 to 4.11-rc1+ (master branch from > > today). All exhibit this behavior with differing frequencies. Earlier > > kernels seem to reproduce the issue less often, while more recent > > kernels reliably exhibit the problem every boot. > > > > How can I further debug this? > > It smells a bit like a DMA / caching issue. > > Can you provide a full kernel log. That might provide some information > about caching that might be relevant (e.g. does dcache have aliases?). The architecture of the BCM1250 SOC used for the BCM91250 boards are fully coherent, S-cache and D-cache are physically indexed and tagged. Only the VIVT (plus the usual ASID tagging) I-cache leaves space for software to screw up cache management but that shouldn't matter for this case, so I suggest to start looking into this from the NFS side. Ralf
