On 10/12/2012 06:36 PM, Jiang Liu wrote:
On 2012-10-12 18:31, Tang Chen wrote:
When the kernel is being initialized, and some hardwares are not added
to system, there won't be acpi_device structs for these devices. But
acpi_is_root_bridge() depends on acpi_device struct. As a result, all
the not-added root bridge will not be judged as a root bridge in
find_root_bridges(). And further more, no handle_hotplug_event_root()
notifier will be installed for them.
This patch introduces a new api to find all root bridges in system by
getting HID directly from ACPI namespace, not depending on acpi_device
struct.
Signed-off-by: Tang Chen<tangchen@xxxxxxxxxxxxxx>
---
drivers/acpi/pci_root.c | 27 ++++++++++++++++++++++-----
1 files changed, 22 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 7d0fb03..3819bee 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -128,9 +128,6 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
/**
* acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
* @handle - the ACPI CA node in question.
- *
- * Note: we could make this API take a struct acpi_device * instead, but
- * for now, it's more convenient to operate on an acpi_handle.
*/
int acpi_is_root_bridge(acpi_handle handle)
{
@@ -138,8 +135,28 @@ int acpi_is_root_bridge(acpi_handle handle)
struct acpi_device *device;
ret = acpi_bus_get_device(handle,&device);
- if (ret)
- return 0;
+ if (ret) {
+ /**
+ * If a device is not added to the system yet, there won't be
+ * an acpi_device struct for it. But it doesn't mean it is not
+ * a PCI root bridge. In this case we need to get HID and CID
+ * from ACPI namespace directly.
+ */
+ struct acpi_device_info *info;
+ acpi_status status;
+ status = acpi_get_object_info(handle,&info);
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_ERR PREFIX "%s: Error reading"
+ "device info\n", __func__);
+ return 0;
+ }
+
+ ret = acpi_match_object_info_ids(info, root_device_ids);
+ if (ret)
+ return 0;
+ else
+ return 1;
+ }
I have sent a similar patch to Yinghai before. For simplicity, we could
use acpi_match_object_info_ids() instead of acpi_match_device_ids()
directly.
Hum, I must have missed it. :)
Using acpi_match_object_info_ids() directly seems good. I'm just worry
about if it could cause any other problem. :)
So now, is this bug fixed ? And we don't need these patches, right ?
Thanks. :)
Thanks!
Gerry
ret = acpi_match_device_ids(device, root_device_ids);
if (ret)
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