On Tue, Feb 12, 2013 at 4:32 PM, Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Feb 12, 2013 at 11:05:28PM +0000, Arnd Bergmann wrote: >> >> Ah, so you only allow hotplugging into the root ports, but not behind >> additional bridges that have active devices on them, right? > >> I guess that is a common limitation for PCIe hotplugging. > > In all the cases I've worked with, it has been a root port hot plug, > but I could imagine something like ExpressCard requiring a second > bridge. > > The standard answer is to leave appropriate gaps. My *guess* on this > matter is that on x86 the gaps are left, as appropriate, by the boot > firmware. Eg an ExpressCard slot will always have a window assigned to > its bridge and Linux would typically not reassign it (or similar). Yes, x86 BIOS will leave some pad number for every pcie root port. Also with patches in git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci-busn-alloc could realloc bus range to get big bus number. 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
