From f055d37346de574635e1fd280f104d5b51e9b3a1 Mon Sep 17 00:00:00 2001
From: Jordan Woyak <jordan.woyak@gmail.com>
Date: Sun, 28 Apr 2019 19:50:36 -0500
Subject: [PATCH] WiimoteEmu: Add game quirk report for reading of EXT/IR input
 directly, which will fail with TAS/NetPlay.

---
 Source/Core/Core/Analytics.cpp                     |  3 ++-
 Source/Core/Core/Analytics.h                       |  4 ++++
 Source/Core/Core/HW/WiimoteEmu/Camera.h            |  3 ++-
 Source/Core/Core/HW/WiimoteEmu/EmuSubroutines.cpp  | 14 ++++++++++++++
 .../Core/Core/HW/WiimoteEmu/Extension/Extension.h  |  3 ++-
 5 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/Source/Core/Core/Analytics.cpp b/Source/Core/Core/Analytics.cpp
index 69a5825094..4486a9708a 100644
--- a/Source/Core/Core/Analytics.cpp
+++ b/Source/Core/Core/Analytics.cpp
@@ -139,7 +139,8 @@ void DolphinAnalytics::ReportGameStart()
 
 // Keep in sync with enum class GameQuirk definition.
 static const char* GAME_QUIRKS_NAMES[] = {
-    "icache-matters",  // ICACHE_MATTERS
+    "icache-matters",
+    "directly-reads-wiimote-input",
 };
 static_assert(sizeof(GAME_QUIRKS_NAMES) / sizeof(GAME_QUIRKS_NAMES[0]) ==
                   static_cast<u32>(GameQuirk::COUNT),
diff --git a/Source/Core/Core/Analytics.h b/Source/Core/Core/Analytics.h
index 0de0f839f8..194e1d1a18 100644
--- a/Source/Core/Core/Analytics.h
+++ b/Source/Core/Core/Analytics.h
@@ -24,6 +24,10 @@ enum class GameQuirk
   // Sometimes code run from ICache is different from its mirror in RAM.
   ICACHE_MATTERS = 0,
 
+  // The Wii remote hardware makes it possible to bypass normal data reporting and directly
+  // "read" extension or IR data. This would break our current TAS/NetPlay implementation.
+  DIRECTLY_READS_WIIMOTE_INPUT,
+
   COUNT,
 };
 
diff --git a/Source/Core/Core/HW/WiimoteEmu/Camera.h b/Source/Core/Core/HW/WiimoteEmu/Camera.h
index 7ad44022f8..29c3d9cd94 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Camera.h
+++ b/Source/Core/Core/HW/WiimoteEmu/Camera.h
@@ -75,6 +75,7 @@ public:
   void SetEnabled(bool is_enabled);
 
   static constexpr u8 I2C_ADDR = 0x58;
+  static constexpr int CAMERA_DATA_BYTES = 36;
 
 private:
   // TODO: some of this memory is write-only and should return error 7.
@@ -89,7 +90,7 @@ private:
     u8 mode;
     u8 unk[3];
     // addr: 0x37
-    u8 camera_data[36];
+    u8 camera_data[CAMERA_DATA_BYTES];
     u8 unk2[165];
   };
 #pragma pack(pop)
diff --git a/Source/Core/Core/HW/WiimoteEmu/EmuSubroutines.cpp b/Source/Core/Core/HW/WiimoteEmu/EmuSubroutines.cpp
index ec5a595597..3320deb47f 100644
--- a/Source/Core/Core/HW/WiimoteEmu/EmuSubroutines.cpp
+++ b/Source/Core/Core/HW/WiimoteEmu/EmuSubroutines.cpp
@@ -12,6 +12,7 @@
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
 #include "Common/Swap.h"
+#include "Core/Analytics.h"
 #include "Core/Core.h"
 #include "Core/HW/WiimoteCommon/WiimoteHid.h"
 #include "Core/HW/WiimoteEmu/WiimoteEmu.h"
@@ -507,6 +508,19 @@ bool Wiimote::ProcessReadDataRequest()
       break;
     }
 
+    // It is possible to bypass data reporting and directly read extension input.
+    // While I am not aware of any games that actually do this,
+    // our NetPlay and TAS methods are completely unprepared for it.
+    const bool is_reading_ext = EncryptedExtension::I2C_ADDR == m_read_request.slave_address &&
+                                m_read_request.address < EncryptedExtension::CONTROLLER_DATA_BYTES;
+    const bool is_reading_ir =
+        CameraLogic::I2C_ADDR == m_read_request.slave_address &&
+        m_read_request.address < CameraLogic::REPORT_DATA_OFFSET + CameraLogic::CAMERA_DATA_BYTES &&
+        m_read_request.address + m_read_request.size > CameraLogic::REPORT_DATA_OFFSET;
+
+    if (is_reading_ext || is_reading_ir)
+      DolphinAnalytics::Instance()->ReportGameQuirk(GameQuirk::DIRECTLY_READS_WIIMOTE_INPUT);
+
     // Top byte of address is ignored on the bus, but it IS maintained in the read-reply.
     auto const bytes_read = m_i2c_bus.BusRead(
         m_read_request.slave_address, (u8)m_read_request.address, bytes_to_read, reply.data);
diff --git a/Source/Core/Core/HW/WiimoteEmu/Extension/Extension.h b/Source/Core/Core/HW/WiimoteEmu/Extension/Extension.h
index d42bdfd3d8..b959f389a8 100644
--- a/Source/Core/Core/HW/WiimoteEmu/Extension/Extension.h
+++ b/Source/Core/Core/HW/WiimoteEmu/Extension/Extension.h
@@ -62,6 +62,7 @@ class EncryptedExtension : public Extension
 {
 public:
   static constexpr u8 I2C_ADDR = 0x52;
+  static constexpr int CONTROLLER_DATA_BYTES = 21;
 
   using Extension::Extension;
 
@@ -76,7 +77,7 @@ protected:
   struct Register
   {
     // 21 bytes of possible extension data
-    u8 controller_data[21];
+    u8 controller_data[CONTROLLER_DATA_BYTES];
 
     u8 unknown2[11];