From 8cf3bb5a1ce01ce69792a5eeeb904a2bb5b366e5 Mon Sep 17 00:00:00 2001
From: Rodrigo Alfonso <rodri042@gmail.com>
Date: Sun, 5 Jan 2025 08:43:51 -0300
Subject: [PATCH] Adding volatile to variables that could change during
 interrupts and are read in main thread to prevent issues with compiler
 optimizations

---
 lib/LinkCable.hpp       | 5 +++--
 lib/LinkMobile.hpp      | 4 ++--
 lib/LinkRawCable.hpp    | 2 +-
 lib/LinkRawWireless.hpp | 9 +++++----
 lib/LinkSPI.hpp         | 4 ++--
 lib/LinkWireless.hpp    | 2 +-
 lib/_link_common.hpp    | 2 ++
 7 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/lib/LinkCable.hpp b/lib/LinkCable.hpp
index dc46976..c3fd990 100644
--- a/lib/LinkCable.hpp
+++ b/lib/LinkCable.hpp
@@ -83,6 +83,7 @@ class LinkCable {
   using u8 = unsigned char;
   using vu32 = volatile unsigned int;
   using vs32 = volatile signed int;
+  using vu8 = volatile unsigned char;
   using U16Queue = Link::Queue<u16, LINK_CABLE_QUEUE_SIZE>;
 
   static constexpr auto BASE_FREQUENCY = Link::_TM_FREQ_1024;
@@ -373,8 +374,8 @@ class LinkCable {
  private:
   struct ExternalState {
     U16Queue syncedIncomingMessages[LINK_CABLE_MAX_PLAYERS];
-    u8 playerCount;
-    u8 currentPlayerId;
+    vu8 playerCount;
+    vu8 currentPlayerId;
   };
 
   struct InternalState {
diff --git a/lib/LinkMobile.hpp b/lib/LinkMobile.hpp
index d3199f0..53eaaab 100644
--- a/lib/LinkMobile.hpp
+++ b/lib/LinkMobile.hpp
@@ -892,8 +892,8 @@ class LinkMobile {
   u32 waitFrames = 0;
   u32 timeoutStateFrames = 0;
   u32 pingFrameCount = 0;
-  Role role = Role::NO_P2P_CONNECTION;
-  State state = NEEDS_RESET;
+  volatile Role role = Role::NO_P2P_CONNECTION;
+  volatile State state = NEEDS_RESET;
   PacketData nextCommandData;
   u32 nextCommandDataSize = 0;
   bool hasPendingTransfer = false;
diff --git a/lib/LinkRawCable.hpp b/lib/LinkRawCable.hpp
index 31145a1..6922427 100644
--- a/lib/LinkRawCable.hpp
+++ b/lib/LinkRawCable.hpp
@@ -258,7 +258,7 @@ class LinkRawCable {
 
  private:
   BaudRate baudRate = BaudRate::BAUD_RATE_1;
-  AsyncState asyncState = IDLE;
+  volatile AsyncState asyncState = IDLE;
   Response asyncData = EMPTY_RESPONSE;
   volatile bool isEnabled = false;
 
diff --git a/lib/LinkRawWireless.hpp b/lib/LinkRawWireless.hpp
index b087186..945918f 100644
--- a/lib/LinkRawWireless.hpp
+++ b/lib/LinkRawWireless.hpp
@@ -51,6 +51,7 @@ class LinkRawWireless {
   using u32 = unsigned int;
   using u16 = unsigned short;
   using u8 = unsigned char;
+  using vu8 = volatile unsigned char;
 
  public:
   static constexpr int PING_WAIT = 50;
@@ -953,9 +954,9 @@ class LinkRawWireless {
   [[nodiscard]] u8 currentPlayerId() { return sessionState.currentPlayerId; }
 
   struct SessionState {
-    u8 playerCount = 1;
-    u8 currentPlayerId = 0;
-    bool isServerClosed = false;
+    vu8 playerCount = 1;
+    vu8 currentPlayerId = 0;
+    volatile bool isServerClosed = false;
   };
 
   struct LoginMemory {
@@ -966,7 +967,7 @@ class LinkRawWireless {
   LinkSPI linkSPI;
   LinkGPIO linkGPIO;
   SessionState sessionState;
-  State state = NEEDS_RESET;
+  volatile State state = NEEDS_RESET;
   volatile bool isEnabled = false;
 
   /**
diff --git a/lib/LinkSPI.hpp b/lib/LinkSPI.hpp
index 35e9784..2bdc374 100644
--- a/lib/LinkSPI.hpp
+++ b/lib/LinkSPI.hpp
@@ -295,8 +295,8 @@ class LinkSPI {
   Mode mode = Mode::SLAVE;
   DataSize dataSize = DataSize::SIZE_32BIT;
   bool waitMode = false;
-  AsyncState asyncState = IDLE;
-  u32 asyncData = 0;
+  volatile AsyncState asyncState = IDLE;
+  volatile u32 asyncData = 0;
   volatile bool isEnabled = false;
 
   void setNormalMode() {
diff --git a/lib/LinkWireless.hpp b/lib/LinkWireless.hpp
index 0432b4d..c38f890 100644
--- a/lib/LinkWireless.hpp
+++ b/lib/LinkWireless.hpp
@@ -981,7 +981,7 @@ class LinkWireless {
   u32 nextAsyncCommandData[LINK_WIRELESS_MAX_COMMAND_TRANSFER_LENGTH];
   u32 nextAsyncCommandDataSize = 0;
   volatile bool isSendingSyncCommand = false;
-  Error lastError = NONE;
+  volatile Error lastError = NONE;
   volatile bool isEnabled = false;
 
 #ifdef LINK_WIRELESS_PUT_ISR_IN_IWRAM
diff --git a/lib/_link_common.hpp b/lib/_link_common.hpp
index f7ca18c..86ccc62 100644
--- a/lib/_link_common.hpp
+++ b/lib/_link_common.hpp
@@ -52,6 +52,8 @@ using vu32 = volatile unsigned int;
 using vs32 = volatile signed int;
 using vu16 = volatile unsigned short;
 using vs16 = volatile signed short;
+using vu8 = volatile unsigned char;
+using vs8 = volatile signed char;
 
 // Structs