[PATCH v11 23/60] PCI: Don't release sibling bridge resources during hotplug

From: Yinghai Lu
Date: Thu Apr 07 2016 - 20:30:27 EST


On hotplug path, we can not touch sibling bridges that is outside
of the slot.

That could happen when BIOS does not assign some bridge BARs and
later kernel can not assign resource to them in first try.

Check if fail dev is the parent bridge, then just use subordinate
bus instead use parent bus.

Reported-by: Andreas Noever <andreas.noever@xxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/setup-bus.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index d3a39b7..4674e6b 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1901,10 +1901,16 @@ again:
* Try to release leaf bridge's resources that doesn't fit resource of
* child device under that bridge
*/
- list_for_each_entry(fail_res, &fail_head, list)
- pci_bus_release_bridge_resources(fail_res->dev->bus,
+ list_for_each_entry(fail_res, &fail_head, list) {
+ struct pci_bus *bus = fail_res->dev->bus;
+
+ if (fail_res->dev == bridge)
+ bus = bridge->subordinate;
+
+ pci_bus_release_bridge_resources(bus,
fail_res->flags & type_mask,
whole_subtree);
+ }

/* restore size and flags */
list_for_each_entry(fail_res, &fail_head, list) {
--
1.8.4.5