IOS: Treat /dev/usb/kbd as blocking

Fixes https://bugs.dolphin-emu.org/issues/13406

Source/Core/Core/IOS/USB/USB_KBD.cpp

@@ -4,7 +4,9 @@
 #include "Core/IOS/USB/USB_KBD.h"
 
 #include <array>
+#include <optional>
 #include <queue>
+#include <string>
 
 #include "Common/FileUtil.h"
 #include "Common/IniFile.h"
@@ -212,15 +214,21 @@ std::optional<IPCReply> USB_KBD::Write(const ReadWriteRequest& request)
 
 std::optional<IPCReply> USB_KBD::IOCtl(const IOCtlRequest& request)
 {
-  if (Config::Get(Config::MAIN_WII_KEYBOARD) && !Core::WantsDeterminism() &&
-      ControlReference::GetInputGate() && !m_message_queue.empty())
-  {
-    auto& system = GetSystem();
-    auto& memory = system.GetMemory();
-    memory.CopyToEmu(request.buffer_out, &m_message_queue.front(), sizeof(MessageData));
-    m_message_queue.pop();
-  }
-  return IPCReply(IPC_SUCCESS);
+  if (request.request != 0)
+    return IPCReply(IPC_EINVAL);
+
+  if (m_pending_request.has_value())
+    return IPCReply(IPC_EEXIST);
+
+  // Blocks until a new event is available
+  m_pending_request = request.address;
+  return std::nullopt;
+}
+
+void USB_KBD::DoState(PointerWrap& p)
+{
+  Device::DoState(p);
+  p.Do(m_pending_request);
 }
 
 bool USB_KBD::IsKeyPressed(int key) const
@@ -309,5 +317,16 @@ void USB_KBD::Update()
 
   if (got_event)
     m_message_queue.emplace(MessageType::Event, modifiers, pressed_keys);
+
+  if (ControlReference::GetInputGate() && !m_message_queue.empty() && m_pending_request.has_value())
+  {
+    auto& system = GetSystem();
+    auto& memory = system.GetMemory();
+    IOCtlRequest pending_request{GetSystem(), m_pending_request.value()};
+    memory.CopyToEmu(pending_request.buffer_out, &m_message_queue.front(), sizeof(MessageData));
+    m_message_queue.pop();
+    GetEmulationKernel().EnqueueIPCReply(pending_request, IPC_SUCCESS);
+    m_pending_request.reset();
+  }
 }
 }  // namespace IOS::HLE

Source/Core/Core/IOS/USB/USB_KBD.h

@@ -4,9 +4,9 @@
 #pragma once
 
 #include <array>
+#include <optional>
 #include <queue>
 #include <string>
-#include <type_traits>
 
 #include "Common/CommonTypes.h"
 #include "Core/IOS/Device.h"
@@ -22,6 +22,7 @@ public:
   std::optional<IPCReply> Open(const OpenRequest& request) override;
   std::optional<IPCReply> Write(const ReadWriteRequest& request) override;
   std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  void DoState(PointerWrap& p) override;
   void Update() override;
 
 private:
@@ -62,5 +63,7 @@ private:
     KBD_LAYOUT_AZERTY = 1
   };
   int m_keyboard_layout = KBD_LAYOUT_QWERTY;
+
+  std::optional<u32> m_pending_request{};
 };
 }  // namespace IOS::HLE

Source/Core/Core/State.cpp

@@ -98,7 +98,7 @@ static size_t s_state_writes_in_queue;
 static std::condition_variable s_state_write_queue_is_empty;
 
 // Don't forget to increase this after doing changes on the savestate system
-constexpr u32 STATE_VERSION = 168;  // Last changed in PR 12639
+constexpr u32 STATE_VERSION = 169;  // Last changed in PR 12338
 
 // Increase this if the StateExtendedHeader definition changes
 constexpr u32 EXTENDED_HEADER_VERSION = 1;  // Last changed in PR 12217