1 files changed, 68 insertions, 5 deletions

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index fc4ccdedb626..83bf145e9ca5 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -84,6 +84,13 @@ MODULE_LICENSE("GPL");
 #define PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_XHCI	0x9c31
 
 #define ASUS_ACPI_UID_ASUSWMI		"ASUSWMI"
+#define ASUS_ACPI_UID_ATK		"ATK"
+
+#define WMI_EVENT_QUEUE_SIZE		0x10
+#define WMI_EVENT_QUEUE_END		0x1
+#define WMI_EVENT_MASK			0xFFFF
+/* The WMI hotkey event value is always the same. */
+#define WMI_EVENT_VALUE_ATK		0xFF
 
 #define WMI_EVENT_MASK			0xFFFF
 
@@ -150,6 +157,7 @@ struct asus_wmi {
 	int dsts_id;
 	int spec;
 	int sfun;
+	bool wmi_event_queue;
 
 	struct input_dev *inputdev;
 	struct backlight_device *backlight_device;
@@ -1738,14 +1746,52 @@ static void asus_wmi_handle_event_code(int code, struct asus_wmi *asus)
 static void asus_wmi_notify(u32 value, void *context)
 {
 	struct asus_wmi *asus = context;
-	int code = asus_wmi_get_event_code(value);
+	int code;
+	int i;
 
-	if (code < 0) {
-		pr_warn("Failed to get notify code: %d\n", code);
-		return;
+	for (i = 0; i < WMI_EVENT_QUEUE_SIZE + 1; i++) {
+		code = asus_wmi_get_event_code(value);
+
+		if (code < 0) {
+			pr_warn("Failed to get notify code: %d\n", code);
+			return;
+		}
+
+		if (code == WMI_EVENT_QUEUE_END || code == WMI_EVENT_MASK)
+			return;
+
+		asus_wmi_handle_event_code(code, asus);
+
+		/*
+		 * Double check that queue is present:
+		 * ATK (with queue) uses 0xff, ASUSWMI (without) 0xd2.
+		 */
+		if (!asus->wmi_event_queue || value != WMI_EVENT_VALUE_ATK)
+			return;
 	}
 
-	asus_wmi_handle_event_code(code, asus);
+	pr_warn("Failed to process event queue, last code: 0x%x\n", code);
+}
+
+static int asus_wmi_notify_queue_flush(struct asus_wmi *asus)
+{
+	int code;
+	int i;
+
+	for (i = 0; i < WMI_EVENT_QUEUE_SIZE + 1; i++) {
+		code = asus_wmi_get_event_code(WMI_EVENT_VALUE_ATK);
+
+		if (code < 0) {
+			pr_warn("Failed to get event during flush: %d\n", code);
+			return code;
+		}
+
+		if (code == WMI_EVENT_QUEUE_END || code == WMI_EVENT_MASK)
+			return 0;
+	}
+
+	pr_warn("Failed to flush event queue\n");
+	return -EIO;
 }
 
 /*
@@ -1944,6 +1990,23 @@ static int asus_wmi_platform_init(struct asus_wmi *asus)
 		asus->dsts_id = ASUS_WMI_METHODID_DSTS;
 	}
 
+	/*
+	 * Some devices can have multiple event codes stored in a queue before
+	 * the module load if it was unloaded intermittently after calling
+	 * the INIT method (enables event handling). The WMI notify handler is
+	 * expected to retrieve all event codes until a retrieved code equals
+	 * queue end marker (One or Ones). Old codes are flushed from the queue
+	 * upon module load. Not enabling this when it should be has minimal
+	 * visible impact so fall back if anything goes wrong.
+	 */
+	wmi_uid = wmi_get_acpi_device_uid(asus->driver->event_guid);
+	if (wmi_uid && !strcmp(wmi_uid, ASUS_ACPI_UID_ATK)) {
+		dev_info(dev, "Detected ATK, enable event queue\n");
+
+		if (!asus_wmi_notify_queue_flush(asus))
+			asus->wmi_event_queue = true;
+	}
+
 	/* CWAP allow to define the behavior of the Fn+F2 key,
 	 * this method doesn't seems to be present on Eee PCs */
 	if (asus->driver->quirks->wapf >= 0)