Re: [PATCH v2] platform/x86: adv_swbutton: use devm_add_action_or_reset() for cleanup

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Wed, 11 Dec 2024, Joe Hattori wrote:

> Current code leaves the device's wakeup enabled in the error path of
> .probe() and .remove(). Also, the registered input device is not
> unregistered. Add a devm_add_action_or_reset() call and cleanup these
> resources in the callback.
> 
> Fixes: 3d904005f686 ("platform/x86: add support for Advantech software defined button")
> Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
> ---
> Changes in V2:
> - Use devm_add_action_or_reset().
> - Call input_unregister_device().
> ---
>  drivers/platform/x86/adv_swbutton.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/platform/x86/adv_swbutton.c b/drivers/platform/x86/adv_swbutton.c
> index 6fa60f3fc53c..5b07c42adfad 100644
> --- a/drivers/platform/x86/adv_swbutton.c
> +++ b/drivers/platform/x86/adv_swbutton.c
> @@ -44,6 +44,14 @@ static void adv_swbutton_notify(acpi_handle handle, u32 event, void *context)
>  	}
>  }
>  
> +static void adv_swbutton_release(void *__input)
> +{
> +	struct input_dev *input = __input;
> +
> +	input_unregister_device(input);

Better but the input device is managed so the unregister call is 
unnecessary.

devm_input_allocate_device() comment says:

 * Managed input devices do not need to be explicitly unregistered or
 * freed as it will be done automatically when owner device unbinds from
 * its driver (or binding fails). Once managed input device is allocated,
 * it is ready to be set up and registered in the same fashion as regular
 * input device. There are no special devm_input_device_[un]register()
 * variants, regular ones work with both managed and unmanaged devices,
 * should you need them. In most cases however, managed input device need
 * not be explicitly unregistered or freed.

-- 
 i.

> +	device_init_wakeup(input->dev.parent, false);
> +}
> +
>  static int adv_swbutton_probe(struct platform_device *device)
>  {
>  	struct adv_swbutton *button;
> @@ -78,6 +86,9 @@ static int adv_swbutton_probe(struct platform_device *device)
>  
>  	device_init_wakeup(&device->dev, true);
>  
> +	if (devm_add_action_or_reset(&device->dev, adv_swbutton_release, input))
> +		return -ENOMEM;
> +
>  	status = acpi_install_notify_handler(handle,
>  					     ACPI_DEVICE_NOTIFY,
>  					     adv_swbutton_notify,
>