From 7f5397abbbc042002fc1b786b76419b0cf65f921 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 10 Sep 2012 17:19:33 -0700 Subject: [PATCH] PCI: Check P2P bridge for invalid secondary/subordinate range commit 1965f66e7db08d1ebccd24a59043eba826cc1ce8 upstream. For bridges with "secondary > subordinate", i.e., invalid bus number apertures, we don't enumerate anything behind the bridge unless the user specified "pci=assign-busses". This patch makes us automatically try to reassign the downstream bus numbers in this case (just for that bridge, not for all bridges as "pci=assign-busses" does). We don't discover all the devices on the Intel DP43BF motherboard without this change (or "pci=assign-busses") because its BIOS configures a bridge as: pci 0000:00:1e.0: PCI bridge to [bus 20-08] (subtractive decode) [bhelgaas: changelog, change message to dev_info] Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=18412 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=625754 Reported-by: Brian C. Huffman Reported-by: VL Tested-by: VL Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 5b3771a7a413..0d5d0bfcb663 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -664,8 +664,10 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, /* Check if setup is sensible at all */ if (!pass && - (primary != bus->number || secondary <= bus->number)) { - dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n"); + (primary != bus->number || secondary <= bus->number || + secondary > subordinate)) { + dev_info(&dev->dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n", + secondary, subordinate); broken = 1; } -- 2.34.1