[PATCH v3 3/3] ACPI / button: Add quirks for initial lid state notification

Lv Zheng
2016-06-01T10:10:55Z

Linux userspace (systemd-logind) keeps on rechecking lid state when the
lid state is closed. If it failed to update the lid state to open after
boot/resume, the system suspending right after the boot/resume could be
resulted.
Graphics drivers also uses the lid notifications to implment
MODESET_ON_LID_OPEN option.

Before the situation is improved from the userspace and from the graphics
driver, users can simply configure ACPI button driver to send initial
"open" lid state using button.lid_init_state=open to avoid such kind of
issues. And our ultimate target should be making
button.lid_init_state=ignore the default behavior. This patch implements
the 2 options and keep the old behavior (button.lid_init_state=method).

Link 1: https://lkml.org/2016/3/7/460
Link 2: https://github.com/systemd/systemd/issues/2087
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: Bastien Nocera: <hadess@hadess.net>
Cc: Benjamin Tissoires <benjamin.tissoires@gmail.com>
---
drivers/acpi/button.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 6e291c1..148f4e5 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -53,6 +53,10 @@
#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"
#define ACPI_BUTTON_TYPE_LID 0x05

+#define ACPI_BUTTON_LID_INIT_IGNORE 0x00
+#define ACPI_BUTTON_LID_INIT_OPEN 0x01
+#define ACPI_BUTTON_LID_INIT_METHOD 0x02
+
#define _COMPONENT ACPI_BUTTON_COMPONENT
ACPI_MODULE_NAME("button");

@@ -105,6 +109,7 @@ struct acpi_button {

static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
static struct acpi_device *lid_device;
+static u8 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;

/* --------------------------------------------------------------------------
FS Interface (/proc)
@@ -285,6 +290,21 @@ static int acpi_lid_update_state(struct acpi_device *device)
return acpi_lid_notify_state(device, state);
}

+static void acpi_lid_initialize_state(struct acpi_device *device)
+{
+ switch (lid_init_state) {
+ case ACPI_BUTTON_LID_INIT_OPEN:
+ (void)acpi_lid_notify_state(device, 1);
+ break;
+ case ACPI_BUTTON_LID_INIT_METHOD:
+ (void)acpi_lid_update_state(device);
+ break;
+ case ACPI_BUTTON_LID_INIT_IGNORE:
+ default:
+ break;
+ }
+}
+
static void acpi_button_notify(struct acpi_device *device, u32 event)
{
struct acpi_button *button = acpi_driver_data(device);
@@ -341,6 +361,8 @@ static int acpi_button_resume(struct device *dev)
struct acpi_button *button = acpi_driver_data(device);

button->suspended = false;
+ if (button->type == ACPI_BUTTON_TYPE_LID)
+ acpi_lid_initialize_state(device);
return 0;
}
#endif
@@ -421,6 +443,7 @@ static int acpi_button_add(struct acpi_device *device)
if (error)
goto err_remove_fs;
if (button->type == ACPI_BUTTON_TYPE_LID) {
+ acpi_lid_initialize_state(device);
/*
* This assumes there's only one lid device, or if there are
* more we only care about the last one...
@@ -450,4 +473,42 @@ static int acpi_button_remove(struct acpi_device *device)
return 0;
}

+static int param_set_lid_init_state(const char *val, struct kernel_param *kp)
+{
+ int result = 0;
+
+ if (!strncmp(val, "open", sizeof("open") - 1)) {
+ lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
+ pr_info("Notify initial lid state as open\n");
+ } else if (!strncmp(val, "method", sizeof("method") - 1)) {
+ lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
+ pr_info("Notify initial lid state with _LID return value\n");
+ } else if (!strncmp(val, "ignore", sizeof("ignore") - 1)) {
+ lid_init_state = ACPI_BUTTON_LID_INIT_IGNORE;
+ pr_info("Do not notify initial lid state\n");
+ } else
+ result = -EINVAL;
+ return result;
+}
+
+static int param_get_lid_init_state(char *buffer, struct kernel_param *kp)
+{
+ switch (lid_init_state) {
+ case ACPI_BUTTON_LID_INIT_OPEN:
+ return sprintf(buffer, "open");
+ case ACPI_BUTTON_LID_INIT_METHOD:
+ return sprintf(buffer, "method");
+ case ACPI_BUTTON_LID_INIT_IGNORE:
+ return sprintf(buffer, "ignore");
+ default:
+ return sprintf(buffer, "invalid");
+ }
+ return 0;
+}
+
+module_param_call(lid_init_state,
+ param_set_lid_init_state, param_get_lid_init_state,
+ NULL, 0644);
+MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
+
module_acpi_driver(acpi_button_driver);
--
1.7.10