On Tue, 2015-05-12 at 17:07 -0500, Brian King wrote: > The mpt2sas driver was changed late last year in that it now requests a 64 bit DMA > mask, then requests a 32 bit coherent DMA mask, then later requests a 64 bit coherent > DMA mask. This was 5fb1bf8aaa832e1e9ca3198de7bbecb8eff7db9c. This breaks 64 bit DMA > support for mpt2sas on Power and we always fall back to using 32 bit DMA. Looking > at the commit log, it looks like this was an intentional change. > > Ben - you had a patch set you had posted to the list back in Feb of this year, but it > doesn't look like it got merged. Right, it was broken, we can't do that unfortunately. It's a hard problem to fix. > https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-February/125087.html > > This would fix the issue I'm seeing on mpt2sas. Do you plan to dust that patch set > off and upstream it? Were there issues with it that still need to be resolved? No that patch doesn't actually work. What we need is essentially a new set of DMA ops that can route an individual map request via the iommu or the bypass window depending on what mask applies. Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
