From: Jiang Liu <jiang....@huawei.com> 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....@huawei.com> Signed-off-by: Yinghai Lu <ying...@kernel.org> Cc: Len Brown <l...@kernel.org> Cc: linux-a...@vger.kernel.org --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/