On Tue, May 24, 2016 at 10:53:08PM +0200, Gabriele Mazzotta wrote:
> Some BIOSes unconditionally send an ACPI notification to RBTN when the
> system is resuming from suspend. This makes dell-rbtn send an input
> event to userspace as if a function key was pressed. Prevent this by
> ignoring all the notifications received while the device is suspended.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=106031
> Signed-off-by: Gabriele Mazzotta <gabriele....@gmail.com>
Gabriele, please include all the maintainers on Cc (Pali was missing).
Pali, can I have your Reviewed-by?
> ---
> drivers/platform/x86/dell-rbtn.c | 56
> ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 56 insertions(+)
>
> diff --git a/drivers/platform/x86/dell-rbtn.c
> b/drivers/platform/x86/dell-rbtn.c
> index 331d63c..dd22fb9 100644
> --- a/drivers/platform/x86/dell-rbtn.c
> +++ b/drivers/platform/x86/dell-rbtn.c
> @@ -28,6 +28,7 @@ struct rbtn_data {
> enum rbtn_type type;
> struct rfkill *rfkill;
> struct input_dev *input_dev;
> + bool suspended;
> };
>
>
> @@ -235,9 +236,55 @@ static const struct acpi_device_id rbtn_ids[] = {
> { "", 0 },
> };
>
> +#ifdef CONFIG_PM_SLEEP
> +static void ACPI_SYSTEM_XFACE rbtn_clear_suspended_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;
> +
> + /*
> + * Upon resume, some BIOSes send an ACPI notification thet triggers
> + * an unwanted input event. In order to ignore it, we use a flag
> + * that we set at suspend and clear once we have received the extra
> + * ACPI notification. Since ACPI notifications are delivered
> + * asynchronously to drivers, we clear the flag from the workqueue
> + * used to deliver the notifications. This should be enough
> + * to have the flag cleared only after we received the extra
> + * notification, if any.
> + */
> + status = acpi_os_execute(OSL_NOTIFY_HANDLER,
> + rbtn_clear_suspended_flag, rbtn_data);
> + if (ACPI_FAILURE(status))
> + rbtn_clear_suspended_flag(rbtn_data);
> +
> + return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(rbtn_pm_ops, rbtn_suspend, rbtn_resume);
> +
> static struct acpi_driver rbtn_driver = {
> .name = "dell-rbtn",
> .ids = rbtn_ids,
> + .drv.pm = &rbtn_pm_ops,
> .ops = {
> .add = rbtn_add,
> .remove = rbtn_remove,
> @@ -399,6 +446,15 @@ static void rbtn_notify(struct acpi_device *device, u32
> event)
> {
> struct rbtn_data *rbtn_data = device->driver_data;
>
> + /*
> + * Some BIOSes send a notification at resume.
> + * Ignore it to prevent unwanted input events.
> + */
> + if (rbtn_data->suspended) {
> + dev_dbg(&device->dev, "ACPI notification ignored\n");
> + return;
> + }
> +
> if (event != 0x80) {
> dev_info(&device->dev, "Received unknown event (0x%x)\n",
> event);
> --
> 2.8.1
>
>
--
Darren Hart
Intel Open Source Technology Center
