Dispatch lux queue only for Asus' HID Usage Page

Some ROG HID keyboards like 0x1866 have multiple IOHIDInterface nubs exposed. In my opinion, the two non-asus nubs handle the normal keyboard keys and have a GenericDesktop(kHIDPage_GenericDesktop) usage page. The nub with Asus' usage page is responsible for handling special Fn key features. Attaching to all three nubs caused backlight inactivity timer issues as our `lastDispatchTime` var is static (meant to be) and multiple queues from different threads wrote to this value causing the value to be overwritten and inconsistent. In this patch, we don't dispatch any queues for non Asus HID pages. So we are assured that only a single thread will read and write to the variable and will hence fix this issue. See issue #4 for detailed discussion on this.

Signed-off-by: black.dragon74 <[email protected]>

ROG-HID-Driver/ROG_HID_Driver.cpp

@@ -78,16 +78,6 @@ kern_return_t IMPL(ROG_HID_Driver, Start)
     }
 
     _hid_interface = interface;
-
-    ret = IODispatchQueue::Create("lux_dispatch_queue", 0, 0, &_lux_queue);
-    if (ret != kIOReturnSuccess)
-    {
-        OSLOG("Failed to create lux dispatch queue");
-        return kIOReturnError;
-    }
-
-    // Load the keyboard backlight inactivity monitor
-    loadKbdLuxMonitor();
 
     OSArray *elements = _hid_interface->getElements();
     elements->retain();
@@ -102,13 +92,16 @@ kern_return_t IMPL(ROG_HID_Driver, Start)
     asusKbdGetFunctions();
 
     // Reflect the intital value on lux
-    DBGLOG("Trying to set initial kbd lux to 0x%x", _current_lux);
+    DBGLOG("Trying to set initial kbd lux to: 0x%x", _current_lux);
     asusKbdBacklightSet(_current_lux);
 
     // And register ourselves with the system
     DBGLOG("Register service");
     RegisterService();
 
+    // Lastly, init the lux queue
+    initLuxQueue();
+
     return ret;
 }
 
@@ -324,7 +317,7 @@ void IMPL(ROG_HID_Driver, loadKbdLuxMonitor)
     }
 
     // Otherwise, init the hook
-    DBGLOG("Lux queue initialized successfully");
+    DBGLOG("Lux queue loaded successfully");
     _last_dispatch_time  = mach_absolute_time();
     _lux_queue->DispatchAsync(^{
         do {
@@ -343,6 +336,58 @@ void IMPL(ROG_HID_Driver, loadKbdLuxMonitor)
     });
 }
 
+void IMPL(ROG_HID_Driver, initLuxQueue)
+{
+    OSDictionary* deviceProps   { nullptr };
+    OSObject* usagePageProp     { nullptr };
+    OSNumber* kbdUsagePage      { nullptr };
+    bool luxQueueSupported      { false };
+
+    // Copy device primary properties
+    _hid_interface->CopyProperties(&deviceProps);
+    if (!deviceProps)
+        goto exit;
+
+    // Read the primary usage page
+    usagePageProp = deviceProps->getObject("PrimaryUsagePage");
+    if (!usagePageProp)
+    {
+        DBGLOG("PrimaryUsagePage key does not exist for this device");
+        goto exit;
+    }
+
+    // PrimaryUsagePage is a 16bit number in native byte order
+    kbdUsagePage = OSDynamicCast(OSNumber, usagePageProp);
+    if (!kbdUsagePage)
+    {
+        DBGLOG("Dynamic cast to OSNumber failed.");
+        goto exit;
+    }
+
+    // Create queue only if vendor is anything but GD
+    luxQueueSupported = kbdUsagePage->unsigned16BitValue() != kHIDPage_GenericDesktop;
+
+    if (luxQueueSupported)
+    {
+        DBGLOG("Creating lux queue for Asus usagePage: 0x%X", kbdUsagePage->unsigned16BitValue());
+        if (IODispatchQueue::Create("lux_dispatch_queue", 0, 0, &_lux_queue) != kIOReturnSuccess)
+        {
+            OSLOG("Failed to create lux queue");
+            goto exit;
+        }
+
+        DBGLOG("Backlight auto turn off is supported, lux queue created successfully");
+        loadKbdLuxMonitor();
+    }
+    else
+    {
+        DBGLOG("Skipping lux queue for non Asus usagePage: 0x%X", kbdUsagePage->unsigned16BitValue());
+    }
+
+exit:
+    OSSafeReleaseNULL(deviceProps);
+}
+
 kern_return_t IMPL(ROG_HID_Driver, Stop)
 {
     DBGLOG("Stop");
@@ -439,7 +484,7 @@ void IMPL(ROG_HID_Driver, asusKbdGetFunctions)
     }
 
     _kbd_function = readBuffer[6];
-    DBGLOG("Keyboard feature report is %02x", _kbd_function);
+    DBGLOG("Keyboard feature report is: 0x%.2X", _kbd_function);
 
 exit:
     report->release();

ROG-HID-Driver/ROG_HID_Driver.iig

@@ -66,6 +66,7 @@ public:
 private:
     virtual void parseKeyboardElementsHook(OSArray* elements);
     virtual void setKbdLux(kLuxEvent luxEvent);
+    virtual void initLuxQueue();
     virtual void loadKbdLuxMonitor();
     virtual void fadeInLux();
     virtual void fadeOutLux();

ROG-HID.xcodeproj/project.pbxproj

@@ -435,7 +435,7 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = 10.15;
-				MARKETING_VERSION = 1.1;
+				MARKETING_VERSION = 1.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.black-dragon74.ROG-HID";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
@@ -460,7 +460,7 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = 10.15;
-				MARKETING_VERSION = 1.1;
+				MARKETING_VERSION = 1.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.black-dragon74.ROG-HID";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;
@@ -482,7 +482,7 @@
 					"$(SDKROOT)/System/DriverKit/System/Library/Frameworks",
 				);
 				INFOPLIST_FILE = "ROG-HID-Driver/Info.plist";
-				MARKETING_VERSION = 1.1;
+				MARKETING_VERSION = 1.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.black-dragon74.ROG-HID-Driver";
 				PRODUCT_NAME = "$(inherited)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
@@ -506,7 +506,7 @@
 					"$(SDKROOT)/System/DriverKit/System/Library/Frameworks",
 				);
 				INFOPLIST_FILE = "ROG-HID-Driver/Info.plist";
-				MARKETING_VERSION = 1.1;
+				MARKETING_VERSION = 1.2;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.black-dragon74.ROG-HID-Driver";
 				PRODUCT_NAME = "$(inherited)";
 				PROVISIONING_PROFILE_SPECIFIER = "";