Re: [PATCH v2] platform/x86: asus-wireless: Fail probe when there is no ACPI match

["Wysocki, Rafael J" <rafael.j.wysocki@intel.com>]

On 7/8/2026 3:07 AM, Linmao Li wrote:
> Every platform driver can be forced to match a device that doesn't match
> its list of device IDs because of device_match_driver_override(), so
> platform drivers that rely on the existence of a device's ACPI companion
> object need to verify its presence.
>
> asus_wireless_probe() returns success when acpi_match_acpi_device()
> finds no match, leaving behind an input device that never reports
> anything because the notify handler is not installed.  Worse, when the
> driver is force-bound to a device without an ACPI companion, probe
> still succeeds and stores a NULL companion pointer, which
> asus_wireless_remove() later passes to acpi_dev_remove_notify_handler(),
> leading to a NULL pointer dereference on unbind.
>
> Return -ENODEV when the device does not match the ID table.  This also
> covers the missing-companion case, because acpi_match_acpi_device()
> rejects a NULL device.
>
> Fixes: f7e648027d7e ("platform/x86: asus-wireless: Convert ACPI driver to a platform one")
> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Signed-off-by: Linmao Li <lilinmao@kylinos.cn>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

(no issues found)

> ---
> v2: Fail probe when the ACPI ID match fails instead of adding a
>      separate ACPI companion check at the top of probe (Rafael).
>
>   drivers/platform/x86/asus-wireless.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/asus-wireless.c b/drivers/platform/x86/asus-wireless.c
> index 2b494bf3cba8..d33853a1baf3 100644
> --- a/drivers/platform/x86/asus-wireless.c
> +++ b/drivers/platform/x86/asus-wireless.c
> @@ -155,7 +155,7 @@ static int asus_wireless_probe(struct platform_device *pdev)
>   
>   	id = acpi_match_acpi_device(device_ids, adev);
>   	if (!id)
> -		return 0;
> +		return -ENODEV;
>   
>   	data->hswc_params = (const struct hswc_params *)id->driver_data;
>