On Tue, 22 Mar 2022 17:27:36 +0000, Robin Murphy <robin.murphy@xxxxxxx> wrote: > > Originally, creating the dma_ranges resource list in pre-sorted fashion > was the simplest and most efficient way to enforce the order required by > iova_reserve_pci_windows(). However since then at least one PCI host > driver is now re-sorting the list for its own probe-time processing, > which doesn't seem entirely unreasonable, so that basic assumption no > longer holds. Make iommu-dma robust and get the sort order it needs by > explicitly sorting, which means we can also save the effort at creation > time and just build the list in whatever natural order the DT had. > > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > --- > > Looking at this area off the back of the XGene thread[1] made me realise > that we need to do it anyway, regardless of whether it might also happen > to restore the previous XGene behaviour or not. Presumably nobody's > tried to use pcie-cadence-host behind an IOMMU yet... This definitely restores PCIe functionality on my Mustang (XGene-1). Hopefully dann can comment on whether this addresses his own issue, as his firmware is significantly different. Thanks, M. -- Without deviation from the norm, progress is not possible.
