From: Jiang Liu <jiang.liu@xxxxxxxxxx>
The code in pci_root_hp.c depends on function acpi_is_root_bridge()
to check whether an ACPI object is a PCI host bridge or not.
If an ACPI device hasn't been created for the ACPI object yet,
function acpi_is_root_bridge() will return false even if the object
is a PCI host bridge object. That behavior will cause two issues:
1) No ACPI notification handler installed for PCI host bridges absent
at startup, so hotplug events for those bridges won't be handled.
2) rescan_root_bridge() can't reenumerate offlined PCI host bridges
because the ACPI devices have been already destroyed.
So use acpi_match_object_info_ids() to correctly detect PCI host bridges.
-v2: update to use acpi_match_object_info_ids() from Tang Chen - Yinghai
-v3: drop the PNP0A008, according to Bjorn.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
---
drivers/acpi/pci_root.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 5ae36d8..d30fb94 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -923,6 +923,23 @@ static void handle_hotplug_event_root(acpi_handle handle, u32 type,
_handle_hotplug_event_root);
}
+static bool acpi_is_root_bridge_object(acpi_handle handle)
+{
+ struct acpi_device_info *info = NULL;
+ acpi_status status;
+ bool ret;
+
+ status = acpi_get_object_info(handle, &info);
+ if (ACPI_FAILURE(status))
+ return false;
+
+ ret = !acpi_match_object_info_ids(info, root_device_ids);
+
+ kfree(info);
+
+ return ret;
+}
+
static acpi_status __init
find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
{
@@ -931,7 +948,7 @@ find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
.pointer = objname };
int *count = (int *)context;
- if (!acpi_is_root_bridge(handle))
+ if (!acpi_is_root_bridge_object(handle))
return AE_OK;
(*count)++;
--
1.7.10.4
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