On Mon, Dec 8, 2014 at 3:00 PM, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > > I think an option would be to keep track of whether the PCI host bridge > can do 64-bit pref above 4G. Yes, that could be enhancement. That should fix the problem Marek's But not on Zermond's, as his system is not using _CRS. Or we can enforce new rule that no _CRS then only use under 4G ? > > If it can't then we know 64-bit pref is always fair game for 32-bit > resources and we can thus downgrade all the bridges 64-pref to 32-perf. > > If it can, then we probably do need to leave it there do real 64-bit > pref, and shoot anything that is 32-bit only down the non-pref windows. > > We *could* try to be smart and scan first to check if anything under the > bridge actually has large/64-bit BARs but that's going to be a heuristic > at best and isn't going to do any good with hotplug. > > I tend to think that treating anything 32-bit pref as non-pref is in > fact the best solution unless we know that the platform doesn't do >>32-bit pref anyway in which case we leave them alone. Yes, but will need to enable pci=realloc automatically, so we can take back control of bridge mmio bar. Thanks Yinghai -- 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
