[RFC PATCH v3 5/5] ACPI: button: Always notify kernel space using _LID returning value

[Lv Zheng]

Both nouveau and i915, the only 2 kernel space lid notification listeners,
invoke acpi_lid_open() API to obtain _LID returning value instead of using
the notified value.

So this patch moves this logic from listeners to lid driver, always notify
kernel space listeners using _LID returning value.

This is a no-op cleanup, but facilitates administrators to configure to
notify kernel drivers with faked lid init states via command line
"button.lid_notify_init_state=Y".

Cc: <intel-gfx@xxxxxxxxxxxxxxxxxxxxx>
Cc: <nouveau@xxxxxxxxxxxxxxxxxxxxx>
Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Cc: Peter Hutterer <peter.hutterer@xxxxxxxxx>
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
 drivers/acpi/button.c             | 16 ++++++++++++++--
 drivers/gpu/drm/i915/intel_lvds.c |  2 +-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 4abf8ae..e047d34 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -119,6 +119,9 @@ static u8 lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
 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");
+static bool lid_notify_init_state __read_mostly = false;
+module_param(lid_notify_init_state, bool, 0644);
+MODULE_PARM_DESC(lid_notify_init_state, "Notify init lid state to kernel drivers after boot/resume");
 
 /* --------------------------------------------------------------------------
                               FS Interface (/proc)
@@ -224,6 +227,15 @@ static void acpi_lid_notify_state(struct acpi_device *device,
 	if (state)
 		pm_wakeup_event(&device->dev, 0);
 
+	if (!lid_notify_init_state) {
+		/*
+		 * There are cases "state" is not a _LID return value, so
+		 * correct it before notification.
+		 */
+		if (!bios_notify &&
+		    lid_init_state != ACPI_BUTTON_LID_INIT_METHOD)
+			state = acpi_lid_evaluate_state(device);
+	}
 	acpi_lid_notifier_call(device, state);
 }
 
@@ -572,10 +584,10 @@ static int param_set_lid_init_state(const char *val, struct kernel_param *kp)
 
 	if (!strncmp(val, "open", sizeof("open") - 1)) {
 		lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
-		pr_info("Notify initial lid state as open\n");
+		pr_info("Notify initial lid state to users space as open and kernel drivers with _LID return value\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");
+		pr_info("Notify initial lid state to user/kernel space 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");
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 9ca4dc4..8ca9080 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -548,7 +548,7 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val,
 	/* Don't force modeset on machines where it causes a GPU lockup */
 	if (dmi_check_system(intel_no_modeset_on_lid))
 		goto exit;
-	if (!acpi_lid_open()) {
+	if (!val) {
 		/* do modeset on next lid open event */
 		dev_priv->modeset_restore = MODESET_ON_LID_OPEN;
 		goto exit;
-- 
2.7.4