Re: [PATCH v4 4/7] ACPI: button: Use input_device_enabled() helper

Dmitry Torokhov
2020-06-25T05:24:55Z

On Mon, Jun 08, 2020 at 01:22:08PM +0200, Andrzej Pietrasiewicz wrote:
> A new helper is available, so use it.
>
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
> ---
> drivers/acpi/button.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index ff7ab291f678..4deb2b48d03c 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -411,7 +411,7 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
> input = button->input;
> if (button->type == ACPI_BUTTON_TYPE_LID) {
> mutex_lock(&button->input->mutex);
> - users = button->input->users;
> + users = input_device_enabled(button->input);
> mutex_unlock(&button->input->mutex);
> if (users)

This chunk (pre-patch) is really wrong. 'users' value is obsolete and
can not be trusted the moment we unlocked the mutex. "if" needs to be
inside critical section.

> acpi_lid_update_state(device, true);
> @@ -460,7 +460,7 @@ static int acpi_button_resume(struct device *dev)
>
> button->suspended = false;
> mutex_lock(&input->mutex);
> - if (button->type == ACPI_BUTTON_TYPE_LID && input->users) {
> + if (button->type == ACPI_BUTTON_TYPE_LID && input_device_enabled(input)) {
> button->last_state = !!acpi_lid_evaluate_state(device);
> button->last_time = ktime_get();
> acpi_lid_initialize_state(device);
> --
> 2.17.1
>

Thanks.

--
Dmitry