[PATCH v4 46/52] PCI: Don't release sibling bridge resources during hotplug

From: Yinghai Lu
Date: Fri Aug 21 2015 - 02:22:36 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 060977c..0c85c0a 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2411,10 +2411,16 @@ 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

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