On Tue, May 9, 2017 at 9:02 AM, Lv Zheng <lv.zheng@xxxxxxxxx> wrote:
> In acpi_lid_notify_state(), it now contains logic to avoid duplicate
> notifications which originally was ensured by using blocking notifier. On
> the contrary, using blocking notifier is wrong as it could keep on
> returning NOTIFY_DONE, causing events lost.
> This patch thus changes lid notification to atomic notifier in order not to
> have events lost.
>
> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
> ---
Looks good to me:
Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Cheers,
Benjamin
> drivers/acpi/button.c | 25 +++++++------------------
> 1 file changed, 7 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index 8b4666f..b91ff86 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -112,7 +112,7 @@ struct acpi_button {
> bool suspended;
> };
>
> -static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
> +static ATOMIC_NOTIFIER_HEAD(acpi_lid_notifier);
> static struct acpi_device *lid_device;
> static u8 lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
>
> @@ -139,10 +139,9 @@ static int acpi_lid_evaluate_state(struct acpi_device *device)
> return lid_state ? 1 : 0;
> }
>
> -static int acpi_lid_notify_state(struct acpi_device *device, int state)
> +static void acpi_lid_notify_state(struct acpi_device *device, int state)
> {
> struct acpi_button *button = acpi_driver_data(device);
> - int ret;
> ktime_t next_report;
> bool do_update;
>
> @@ -220,18 +219,7 @@ static int acpi_lid_notify_state(struct acpi_device *device, int state)
> if (state)
> pm_wakeup_event(&device->dev, 0);
>
> - ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
> - if (ret == NOTIFY_DONE)
> - ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,
> - device);
> - if (ret == NOTIFY_DONE || ret == NOTIFY_OK) {
> - /*
> - * It is also regarded as success if the notifier_chain
> - * returns NOTIFY_OK or NOTIFY_DONE.
> - */
> - ret = 0;
> - }
> - return ret;
> + atomic_notifier_call_chain(&acpi_lid_notifier, state, device);
> }
>
> static int acpi_button_state_seq_show(struct seq_file *seq, void *offset)
> @@ -342,13 +330,13 @@ static int acpi_button_remove_fs(struct acpi_device *device)
> -------------------------------------------------------------------------- */
> int acpi_lid_notifier_register(struct notifier_block *nb)
> {
> - return blocking_notifier_chain_register(&acpi_lid_notifier, nb);
> + return atomic_notifier_chain_register(&acpi_lid_notifier, nb);
> }
> EXPORT_SYMBOL(acpi_lid_notifier_register);
>
> int acpi_lid_notifier_unregister(struct notifier_block *nb)
> {
> - return blocking_notifier_chain_unregister(&acpi_lid_notifier, nb);
> + return atomic_notifier_chain_unregister(&acpi_lid_notifier, nb);
> }
> EXPORT_SYMBOL(acpi_lid_notifier_unregister);
>
> @@ -369,7 +357,8 @@ static int acpi_lid_update_state(struct acpi_device *device)
> if (state < 0)
> return state;
>
> - return acpi_lid_notify_state(device, state);
> + acpi_lid_notify_state(device, state);
> + return 0;
> }
>
> static void acpi_lid_initialize_state(struct acpi_device *device)
> --
> 2.7.4
>
> --
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