There are many AML tables reporting wrong initial lid state (Link 1), and some of them never report lid open state (Link 2). Thus, the usage model of the ACPI control method lid device is: 1. The initial lid state returned from _LID is not reliable; 2. The lid open event is not reliable; 3. The lid close event is always reliable, used by the platform firmware to trigger OSPM power saving operations. Then we can see an issue in the current ACPI button driver. When the initial lid state is "close" and the platform never reports "open", we can see that the userspace could only recieve "close" once. And all follow-up "close" events can never trigger OSPM power saving operations. This is because of the type of the lid events. The SW_LID is a switch event, only the switched value will be delivered to the userspace. When the value never switches, nothing can be seen by the userspace. Currently ACPI button driver implements a lid_init_state=open quirk to send additional "open" after resuming in order to avoid another issue that the system may be suspended right after resuming because the userspace programs have strict requirement of the "open" event. However, this breaks some usage model (e.x., the dark resume scenario). So we need to stop sending the additional "open" event and switch the driver to lid_init_state=ignore mode. The userspace programs should also be changed to stop being strict to the "open" event. This is the preferred mode for the Linux ACPI button driver and the userspace programs to work together on such buggy platforms. However, we can see that, without fixing the issue mentioned in the 2nd paragraph, subsequent platform triggered "close" events cannot be delivered to the userspace and the power saving operations can not be triggered. So we need to fix the issue before the userspace changes its behavior. This patch adds a mechanism to insert lid events as a compensation for the platform triggered ones to form a complete event switches in order to make the "close" switch events always reliable. Link 1: https://bugzilla.kernel.org/show_bug.cgi?id=89211 https://bugzilla.kernel.org/show_bug.cgi?id=106151 Link 2: https://bugzilla.kernel.org/show_bug.cgi?id=106941 Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> Suggested-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx> Cc: Bastien Nocera: <hadess@xxxxxxxxxx> Cc: linux-input@xxxxxxxxxxxxxxx --- drivers/acpi/button.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c index 148f4e5..7e2a9eb 100644 --- a/drivers/acpi/button.c +++ b/drivers/acpi/button.c @@ -104,6 +104,8 @@ struct acpi_button { struct input_dev *input; char phys[32]; /* for input device */ unsigned long pushed; + int last_state; + unsigned long last_time; bool suspended; }; @@ -111,6 +113,10 @@ static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier); static struct acpi_device *lid_device; static u8 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD; +static unsigned long lid_report_interval __read_mostly = 500; +module_param(lid_report_interval, ulong, 0644); +MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events"); + /* -------------------------------------------------------------------------- FS Interface (/proc) -------------------------------------------------------------------------- */ @@ -133,11 +139,22 @@ static int acpi_lid_evaluate_state(struct acpi_device *device) static int acpi_lid_notify_state(struct acpi_device *device, int state) { struct acpi_button *button = acpi_driver_data(device); + unsigned long timeout; int ret; - /* input layer checks if event is redundant */ + /* Send the switch event */ + timeout = button->last_time + + msecs_to_jiffies(lid_report_interval); + if (time_after(jiffies, timeout) && + (button->last_state == !!state)) { + /* Send the complement switch event */ + input_report_switch(button->input, SW_LID, state); + input_sync(button->input); + } input_report_switch(button->input, SW_LID, !state); input_sync(button->input); + button->last_state = !!state; + button->last_time = jiffies; if (state) pm_wakeup_event(&device->dev, 0); @@ -407,6 +424,8 @@ static int acpi_button_add(struct acpi_device *device) strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID); sprintf(class, "%s/%s", ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID); + button->last_state = !!acpi_lid_evaluate_state(device); + button->last_time = jiffies; } else { printk(KERN_ERR PREFIX "Unsupported hid [%s]\n", hid); error = -ENODEV; -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
