On Wed, Jun 24, 2015 at 08:34:28AM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2014-09-29 at 12:17 -0600, Bjorn Helgaas wrote: > > This seems like more than necessary, but I don't know all the history. > > In particular, I don't know why PCI_PROBE_ONLY should make a > > difference to things like claiming resources. > > It shouldn't ... we created that option on ppc originally to avoid > allocation/reallocation of resources. If they are bad, leave them bad, > but it was never a question of disabling all these other things. > > (Ok, the MRSS/MPS is debatable, but why not plumb the parent pointers > and why not claim ? That doesn't make sense to me). You could look back over the history of arch/arm/kernel/bios32.c and see that it was introduced by Will Deacon when he stripped out the ARM version in favour of the generic version, and was found to be necessary then. I think the question has to be asked (based upon what Ben's saying) and what's identified in these commits as a failure case (pci_enable_resource failing when PCI_PROBE_ONLY is enabled) - why is the PCI core creating per-device resources which do not have parents. I've no idea on that; the only ARM boxes I have use the kernel's PCI allocation, I don't have these boxes which want to use PCI_PROBE_ONLY so it's something I have zero knowledge of. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- 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
