On Thu, Nov 8, 2018 at 11:49 PM, Christoph Hellwig <h...@lst.de> wrote: > On Tue, Nov 06, 2018 at 05:27:14PM -0800, John Stultz wrote: >> But at that point if I just re-apply "swiotlb: use swiotlb_map_page in >> swiotlb_map_sg_attrs", I reproduce the hangs. >> >> Any suggestions for how to further debug what might be going wrong >> would be appreciated! > > Very odd. In the end map_sg and map_page are defined to do the same > things to start with. The only real issue we had in this area was: > > "[PATCH v2] of/device: Really only set bus DMA mask when appropriate" > > so with current mainline + that you still see a problem, and if you > rever the commit we are replying to it still goes away?
Just to confirm, as of 4.20-rc2 (which includes the of/device patch above), I'm still seeing this issue, but it isn't as reliable to reproduce as before. With "swiotlb: use swiotlb_map_page in swiotlb_map_sg_attrs" reverted (along with the dependent swiotlb patches) it doesn't seem to trigger (no matter what I try). But re-applying that patch it tends to trigger by itself at boot up, but sometimes I have to run "find /" to trigger the io hang/stall. thanks -john _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
