From: Yinghai Lu Date: Mon, 30 Jan 2012 11:25:24 +0000 (+0100) Subject: PCI: workaround hard-wired bus number V2 X-Git-Tag: firefly_0821_release~7541^2~1732 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=e4907ec10117f491d4a5630994a04bc0d3a7d0f1;p=firefly-linux-kernel-4.4.55.git PCI: workaround hard-wired bus number V2 commit 71f6bd4a23130cd2f4b036010c5790b1295290b9 upstream. Fixes PCI device detection on IBM xSeries IBM 3850 M2 / x3950 M2 when using ACPI resources (_CRS). This is default, a manual workaround (without this patch) would be pci=nocrs boot param. V2: Add dev_warn if the workaround is hit. This should reveal how common such setups are (via google) and point to possible problems if things are still not working as expected. -> Suggested by Jan Beulich. Tested-by: garyhade@us.ibm.com Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index bafb3c3d4a89..5b3771a7a413 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -657,6 +657,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, dev_dbg(&dev->dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n", secondary, subordinate, pass); + if (!primary && (primary != bus->number) && secondary && subordinate) { + dev_warn(&dev->dev, "Primary bus is hard wired to 0\n"); + primary = bus->number; + } + /* Check if setup is sensible at all */ if (!pass && (primary != bus->number || secondary <= bus->number)) {