PCI: workaround hard-wired bus number V2
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.
Cc: stable@vger.kernel.org
Tested-by: garyhade@us.ibm.com
Signed-off-by: Yinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 7cc9e2f..71eac9c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -651,6 +651,11 @@
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)) {
