feat: A2DP bluetooth audio working

kernel/src/Drivers/USB/Bluetooth/Bluetooth.cpp

@@ -218,15 +218,32 @@ namespace Drivers::USB::Bluetooth {
         // Set local name
         Hci::WriteLocalName("MontaukOS");
 
-        // Set class of device: Audio (Major Service: Audio, Major Class: Audio/Video)
-        // CoD: 0x240404 = Rendering | Audio | Wearable Headset (common for audio devices)
-        // For a computer acting as audio source:
-        // 0x200408 = Audio service | Audio/Video class | Portable Audio
-        Hci::WriteClassOfDevice(0x200408);
+        // Class of Device.  The A2DP spec MANDATES the Capturing service bit
+        // (0x080000) for a source; Audio (0x200000) is customary.  Major/minor
+        // class: Computer/Laptop (0x010C) -- what we actually are.  The old
+        // value 0x200408 (Audio/Video major class, minor "hands-free device",
+        // no Capturing bit) presented MontaukOS to the headset as ANOTHER
+        // HEADSET.  A sink's connection manager classifies peers by CoD (it
+        // arrives in its Connection Request event and is cached at pairing),
+        // and an A2DP/AVRCP dial from a "hands-free unit" is a credible reason
+        // for it to park those channels at "authorization pending" forever.
+        // NOTE: the headset caches this from pairing -- it must FORGET the
+        // device and re-pair to observe the new class.
+        Hci::WriteClassOfDevice(0x28010C);
 
         // Enable Simple Secure Pairing
         Hci::WriteSSPMode(1);
 
+        // Allow role switch + sniff on new connections.  The controller default
+        // link policy is 0x0000 (deny both).  A multipoint headset (Bose QC
+        // Ultra) that also holds a link to a phone requests a role switch to
+        // master on our link to avoid a scatternet; with the switch denied,
+        // some sink firmwares never grant the A2DP media path.  Sniff denial
+        // similarly upsets CSR-derived stacks that sniff idle links.
+        uint8_t linkPolicy[2] = {0x05, 0x00};   // bit0 role switch, bit2 sniff
+        Hci::SendCommand(Hci::OP_WRITE_DEFAULT_LP, linkPolicy, 2);
+        Hci::WaitCommandComplete(Hci::OP_WRITE_DEFAULT_LP);
+
         // Set event mask to receive relevant events.  Octet 6 (events 0x31-0x38)
         // MUST be enabled for Secure Simple Pairing: IO Capability Request
         // (0x31, bit 48), IO Capability Response (0x32), User Confirmation
@@ -261,6 +278,19 @@ namespace Drivers::USB::Bluetooth {
         CompleteInit();
     }
 
+    // =========================================================================
+    // ServiceEvents — steady-state event pump (idle loop)
+    // =========================================================================
+
+    void ServiceEvents() {
+        if (!g_initialized) return;
+        if (Xhci::InPollContext()) return;   // never nest under PollEvents
+        Xhci::PollEvents();
+        Hci::DrainEvents();
+        Hci::ProcessPendingCommands();
+        A2dp::PumpMedia();   // feed queued media to the link (no-op when idle)
+    }
+
     // =========================================================================
     // Public queries
     // =========================================================================