Re: [PATCH v3] dell-rbtn: Ignore ACPI notifications if device is suspended

From: Pali RohÃr
Date: Mon Mar 21 2016 - 08:17:44 EST


On Friday 18 March 2016 23:44:23 Gabriele Mazzotta wrote:
> +#ifdef CONFIG_PM_SLEEP
> +static void ACPI_SYSTEM_XFACE rbtn_acpi_clear_flag(void *context)
> +{
> + struct rbtn_data *rbtn_data = context;
> +
> + rbtn_data->suspended = false;
> +}
> +
> +static int rbtn_suspend(struct device *dev)
> +{
> + struct acpi_device *device = to_acpi_device(dev);
> + struct rbtn_data *rbtn_data = acpi_driver_data(device);
> +
> + rbtn_data->suspended = true;
> +
> + return 0;
> +}
> +
> +static int rbtn_resume(struct device *dev)
> +{
> + struct acpi_device *device = to_acpi_device(dev);
> + struct rbtn_data *rbtn_data = acpi_driver_data(device);
> + acpi_status status;
> +
> + /*
> + * Clear the flag only after we received the extra
> + * ACPI notification.
> + */
> + status = acpi_os_execute(OSL_NOTIFY_HANDLER,
> + rbtn_acpi_clear_flag, rbtn_data);
> + if (ACPI_FAILURE(status))
> + rbtn_data->suspended = false;

I case when acpi_os_execute success it calls rbtn_acpi_clear_flag,
right? And that will set suspended to false. When acpi_os_execute fails,
then it set suspended too to false... Then whole acpi_os_execute doing
just "barrier" after which suspended flag can be set to false. So I
think rbtn_acpi_clear_flag function is not needed here.

Cannot you pass NULL or empty function pointer as callback? Or what was
reason to do that flag clearing at "two places"?

> + return 0;
> +}
> +#endif

--
Pali RohÃr
pali.rohar@xxxxxxxxx