There is a sanity checker in the end of pci_scan_child_bus_extend() that
tries to detect badly configured bridges. For example given the below
topology:
+-1b.0-[01-39]----00.0-[02-3a]--+-00.0-[03]----00.0
+-01.0-[04-39]--
\-02.0-[3a]----00.0
The sanity checker notices this and logs following messages:
pci_bus 0000:3a: [bus 3a] partially hidden behind bridge 0000:02 [bus 02-39]
pci_bus 0000:3a: [bus 3a] partially hidden behind bridge 0000:01 [bus 01-39]
This is not really helpful to users and the information above is not
even correct (0000:02 is a bus not bridge). Make this a bit more
understandable by changing the sanity checker to log following message
in place of the above two messages:
pci 0000:02:02.0: devices behind bridge are unusable, because [bus 3a] cannot be assigned for them
While there update the comment on top of the sanity checker block to
make it clear that it is not only restricted to CardBus.
Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/pci/probe.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index a0c48aa1c42f..10084990fbc3 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1191,20 +1191,16 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
(is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
pci_domain_nr(bus), child->number);
- /* Has only triggered on CardBus, fixup is in yenta_socket */
+ /* Check that all devices are accessible */
while (bus->parent) {
if ((child->busn_res.end > bus->busn_res.end) ||
(child->number > bus->busn_res.end) ||
(child->number < bus->number) ||
(child->busn_res.end < bus->number)) {
- dev_info(&child->dev, "%pR %s hidden behind%s bridge %s %pR\n",
- &child->busn_res,
- (bus->number > child->busn_res.end &&
- bus->busn_res.end < child->number) ?
- "wholly" : "partially",
- bus->self->transparent ? " transparent" : "",
- dev_name(&bus->dev),
- &bus->busn_res);
+ dev_info(&dev->dev,
+ "devices behind bridge are unusable, because %pR cannot be assigned for them\n",
+ &child->busn_res);
+ break;
}
bus = bus->parent;
}
--
2.17.0
