On Wed, 2015-04-08 at 17:06 -0700, Yinghai Lu wrote: > On Wed, Apr 8, 2015 at 2:12 PM, Benjamin Herrenschmidt > <benh@xxxxxxxxxxxxxxxxxxx> wrote: > > > Thanks Bjorn. We can fix Yinghai patch for 4.2, it would be indeed handy > > even for us to be able to support putting 64-bit NP BARs in prefetch > > windows (For some SR-IOV adapters for example) too, but we need to do it > > right. > > Please check if you are ok with attached. I'll let Bjorn be the final judge here but I am not fan of the way you set/clear/set/clear the IORESOURCE_PREFETCH bit with pci_set_pref_under_pref(). It's error prone and confusing, the code is already barely readable as it is ... I would rather you replace those various masks compares with a helper that does something like pci_resource_compatible(parent_res, child_res), which has the logic to test. That or a helper that does something like pci_calc_compatible_res_flags() which returns a "flags" that has PREFETCH set, which you use in place of res->flags in the various allocation path. As-is, your patch looks like a band-aid and smells like a hack :-) Ben. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html