[PATCH v2] ACPI: scan: fix bus ID cleanup on device_add() failure

[Hongyan Xu <getshell@seu.edu.cn>]

When device_add() fails after acpi_device_set_name() has allocated an
instance ID and linked a new acpi_device_bus_id into acpi_bus_id_list, the
rollback path only removes wakeup_list and detaches the ACPI handle data.

That leaves the bus-ID bookkeeping behind and keeps the allocated instance
number consumed.

Move the bus-ID cleanup and wakeup-list removal into a single helper.
Use it from both the normal device teardown path and the device_add()
rollback path. The wakeup list node is initialized before registration, so
it can be deleted without checking whether the device is wakeup-capable, as
in the original teardown path.

Found by manual review of reports from the
kernel70rc2-fail11-retry-20260801 run.

Signed-off-by: Hongyan Xu <getshell@seu.edu.cn>
---
v2:
- Fold the bus-ID cleanup and wakeup-list removal into one helper to avoid
  duplicating the same sequence in acpi_device_del() and the device_add()
  rollback path.
- Drop the wakeup.flags.valid check before list_del(&device->wakeup_list).

v1: https://lore.kernel.org/linux-acpi/20260804154854.1555-1-getshell@seu.edu.cn/

 drivers/acpi/scan.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index ff7000b71fd1..a311af60d8d3 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -520,12 +520,10 @@ static void acpi_device_release(struct device *dev)
 	kfree(acpi_dev);
 }
 
-static void acpi_device_del(struct acpi_device *device)
+static void acpi_device_del_list(struct acpi_device *device)
 {
 	struct acpi_device_bus_id *acpi_device_bus_id;
 
-	mutex_lock(&acpi_device_lock);
-
 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 		if (!strcmp(acpi_device_bus_id->bus_id,
 			    acpi_device_hid(device))) {
@@ -540,6 +538,13 @@ static void acpi_device_del(struct acpi_device *device)
 		}
 
 	list_del(&device->wakeup_list);
+}
+
+static void acpi_device_del(struct acpi_device *device)
+{
+	mutex_lock(&acpi_device_lock);
+
+	acpi_device_del_list(device);
 
 	mutex_unlock(&acpi_device_lock);
 
@@ -800,7 +805,7 @@ int acpi_device_add(struct acpi_device *device)
 err:
 	mutex_lock(&acpi_device_lock);
 
-	list_del(&device->wakeup_list);
+	acpi_device_del_list(device);
 
 err_unlock:
 	mutex_unlock(&acpi_device_lock);
-- 
2.50.1.windows.1