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

On Sat, Aug 8, 2026 at 10:59 AM Hongyan Xu <[email protected]> wrote:
>
> 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 <[email protected]>

Applied (with some non-essential modifications) as 7.3 material, thanks!

> ---
> 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/[email protected]/
>
>  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