[Very RFC 38/46] powerpc/pci-hotplug: Scan the whole bus when using PCI_PROBE_NORMAL
From: Oliver O'Halloran <oohall@gmail.com>
Date: 2019-11-20 02:46:13
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Currently when using the normal (i.e not building pci_dev's from the DT node) probe method we only scan the devfn corresponding to the first child of the bridge's DT node. This doesn't make much sense to me, but it seems to have worked so far. At a guess it seems to work because in a PCIe environment the first downstream child will be at devfn 00.0. In any case it's completely broken when no pci_dn is available. Remove the PCI_DN checking and scan each of the device number that might be on the downstream bus. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> --- I'm not sure we should be using pci_scan_slot() directly here. Maybe there's some insane legacy reason for it. --- arch/powerpc/kernel/pci-hotplug.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c
index d6a67f814983..85299c769768 100644
--- a/arch/powerpc/kernel/pci-hotplug.c
+++ b/arch/powerpc/kernel/pci-hotplug.c@@ -123,17 +123,10 @@ void pci_hp_add_devices(struct pci_bus *bus) if (mode == PCI_PROBE_DEVTREE) { /* use ofdt-based probe */ of_rescan_bus(dn, bus); - } else if (mode == PCI_PROBE_NORMAL && - dn->child && PCI_DN(dn->child)) { - /* - * Use legacy probe. In the partial hotplug case, we - * probably have grandchildren devices unplugged. So - * we don't check the return value from pci_scan_slot() in - * order for fully rescan all the way down to pick them up. - * They can have been removed during partial hotplug. - */ - slotno = PCI_SLOT(PCI_DN(dn->child)->devfn); - pci_scan_slot(bus, PCI_DEVFN(slotno, 0)); + } else if (mode == PCI_PROBE_NORMAL) { + for (slotno = 0; slotno < 255; slotno += 8) + pci_scan_slot(bus, slotno); + max = bus->busn_res.start; /* * Scan bridges that are already configured. We don't touch
--
2.21.0