diff options
Diffstat (limited to 'drivers/acpi/button.c')
| -rw-r--r-- | drivers/acpi/button.c | 85 |
1 files changed, 82 insertions, 3 deletions
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c index 31abb0bdd4f2..e19f530f1083 100644 --- a/drivers/acpi/button.c +++ b/drivers/acpi/button.c @@ -19,6 +19,8 @@ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ +#define pr_fmt(fmt) "ACPI : button: " fmt + #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> @@ -104,6 +106,8 @@ struct acpi_button { struct input_dev *input; char phys[32]; /* for input device */ unsigned long pushed; + int last_state; + ktime_t last_time; bool suspended; }; @@ -111,6 +115,10 @@ 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) -------------------------------------------------------------------------- */ @@ -134,10 +142,79 @@ static int 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; + + /* + * In lid_init_state=ignore mode, if user opens/closes lid + * frequently with "open" missing, and "last_time" is also updated + * frequently, "close" cannot be delivered to the userspace. + * So "last_time" is only updated after a timeout or an actual + * switch. + */ + if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE || + button->last_state != !!state) + do_update = true; + else + do_update = false; + + next_report = ktime_add(button->last_time, + ms_to_ktime(lid_report_interval)); + if (button->last_state == !!state && + ktime_after(ktime_get(), next_report)) { + /* Complain the buggy firmware */ + pr_warn_once("The lid device is not compliant to SW_LID.\n"); - /* input layer checks if event is redundant */ - input_report_switch(button->input, SW_LID, !state); - input_sync(button->input); + /* + * Send the unreliable complement switch event: + * + * On most platforms, the lid device is reliable. However + * there are exceptions: + * 1. Platforms returning initial lid state as "close" by + * default after booting/resuming: + * https://bugzilla.kernel.org/show_bug.cgi?id=89211 + * https://bugzilla.kernel.org/show_bug.cgi?id=106151 + * 2. Platforms never reporting "open" events: + * https://bugzilla.kernel.org/show_bug.cgi?id=106941 + * On these buggy platforms, the usage model of the ACPI + * lid device actually is: + * 1. The initial returning value of _LID may not be + * reliable. + * 2. The open event may not be reliable. + * 3. The close event is reliable. + * + * But SW_LID is typed as input switch event, the input + * layer checks if the event is redundant. Hence if the + * state is not switched, the userspace cannot see this + * platform triggered reliable event. By inserting a + * complement switch event, it then is guaranteed that the + * platform triggered reliable one can always be seen by + * the userspace. + */ + if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) { + do_update = true; + /* + * Do generate complement switch event for "close" + * as "close" is reliable and wrong "open" won't + * trigger unexpected behaviors. + * Do not generate complement switch event for + * "open" as "open" is not reliable and wrong + * "close" will trigger unexpected behaviors. + */ + if (!state) { + input_report_switch(button->input, + SW_LID, state); + input_sync(button->input); + } + } + } + /* Send the platform triggered reliable event */ + if (do_update) { + input_report_switch(button->input, SW_LID, !state); + input_sync(button->input); + button->last_state = !!state; + button->last_time = ktime_get(); + } if (state) pm_wakeup_event(&device->dev, 0); @@ -411,6 +488,8 @@ 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 = ktime_get(); } else { printk(KERN_ERR PREFIX "Unsupported hid [%s]\n", hid); error = -ENODEV; |