On Mon, Feb 6, 2012 at 9:14 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > The current bus number allocation in pci_scan_bridge() is very simple > -- we just add one to the highest-numbered bridge we've seen. That > works in many cases, but it means any holes in the range of used bus > numbers are just wasted. > > Here's a case I tripped over where the current scheme fails. The > machine boots with bridge 00:03.0 to [bus 05-19]. Now we hot-add a > hierarchy that is currently configured like this: > > 05:00.0 bridge to [bus 06-1e] > 06:05.0 bridge to [bus 1c] > 06:06.0 bridge to [bus 1d] > 1c:00.0 NIC0 > 1d:00.0 NIC1 > > [bus 1a-1e] is inaccessible because the 00:03.0 aperture only includes > [bus 05-19]. There's plenty of space to reconfigure the hierarchy, > e.g., to make 05:00.0 lead to [bus 06-19], 06:05.0 lead to [bus 18], > and 06:06.0 lead to [bus 19]. But we aren't smart enough to do that. Yes, this patchset will reject 05:00.0 bus setting from bios, and assign it with 06-19. 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
