On Thu, Jun 23, 2016 at 01:04:01PM +0100, Robin Murphy wrote: > On 23/06/16 06:01, Jon Masters wrote: > >On 05/11/2016 10:26 AM, Robin Murphy wrote: > >>(I have no actual objection to this patch, though, and at this point > >>I'm just chucking ideas about). > > > >Can I ask what the next steps are here? We're looking for upstream > >direction to guide some internal activities and could really do with > >understanding how you'd like to solve this one longer term as well as > >what interim solution could be acceptable until we get there. > > Well, for now I'm planning to leave the explicit "terminate the > alias walk from the callback function" behaviour in the DT-parsing > code[1], since there doesn't seem any good reason not to. As Bjorn > says, though, it probably is generally useful for the PCI code to > have its own knowledge of exactly where DMA can escape the PCI > hierarchy - I now wonder if we could actually just do that from the > DT/IORT code; if firmware says a particular bridge/etc. has a > relationship with an ITS or SMMU, then presumably it's reasonable to > infer that DMA can come out of it, thus we could inform the PCI code > there and then without it having to quirk things on its own? > > Robin. > > [1]:http://article.gmane.org/gmane.linux.kernel.iommu/13932 Just a reminder that I'm going to be on vacation for about the next three weeks, so it's not that I'm ignoring this, but it seems like it's not fully baked quite yet. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
