Merge pull request #1854 from JosJuice/read-disc-after-delay

DVDInterface: Read disc after delay, not before

Source/Core/Core/CoreTiming.cpp

@@ -234,8 +234,14 @@ void ScheduleEvent_Threadsafe(int cyclesIntoFuture, int event_type, u64 userdata
 	tsQueue.Push(ne);
 }
 
+// Executes an event immediately, then returns.
+void ScheduleEvent_Immediate(int event_type, u64 userdata)
+{
+	event_types[event_type].callback(userdata, 0);
+}
+
 // Same as ScheduleEvent_Threadsafe(0, ...) EXCEPT if we are already on the CPU thread
-// in which case the event will get handled immediately, before returning.
+// in which case this is the same as ScheduleEvent_Immediate.
 void ScheduleEvent_Threadsafe_Immediate(int event_type, u64 userdata)
 {
 	if (Core::IsCPUThread())

Source/Core/Core/CoreTiming.h

@@ -43,11 +43,11 @@ void DoState(PointerWrap &p);
 int RegisterEvent(const std::string& name, TimedCallback callback);
 void UnregisterAllEvents();
 
-// userdata MAY NOT CONTAIN POINTERS. userdata might get written and reloaded from disk,
+// userdata MAY NOT CONTAIN POINTERS. userdata might get written and reloaded from savestates.
-// when we implement state saves.
+void ScheduleEvent(int cyclesIntoFuture, int event_type, u64 userdata = 0);
-void ScheduleEvent(int cyclesIntoFuture, int event_type, u64 userdata=0);
+void ScheduleEvent_Immediate(int event_type, u64 userdata = 0);
-void ScheduleEvent_Threadsafe(int cyclesIntoFuture, int event_type, u64 userdata=0);
+void ScheduleEvent_Threadsafe(int cyclesIntoFuture, int event_type, u64 userdata = 0);
-void ScheduleEvent_Threadsafe_Immediate(int event_type, u64 userdata=0);
+void ScheduleEvent_Threadsafe_Immediate(int event_type, u64 userdata = 0);
 
 // We only permit one event of each type in the queue at a time.
 void RemoveEvent(int event_type);

Source/Core/Core/HW/DVDInterface.cpp

@@ -213,6 +213,22 @@ union UDICFG
 	UDICFG(u32 _hex) {Hex = _hex;}
 };
 
+struct DVDReadCommand
+{
+	bool is_valid;
+
+	u64 DVD_offset;
+	u32 output_address;
+	u32 length;
+	bool decrypt;
+
+	DIInterruptType interrupt_type;
+
+	// Used to notify emulated software after executing command.
+	// Pointers don't work with savestates, so CoreTiming events are used instead
+	int callback_event_type;
+};
+
 
 // STATE_TO_SAVE
 // hardware registers
@@ -225,6 +241,8 @@ static UDICR     m_DICR;
 static UDIIMMBUF m_DIIMMBUF;
 static UDICFG    m_DICFG;
 
+static DVDReadCommand current_read_command;
+
 static u32 AudioPos;
 static u32 CurrentStart;
 static u32 CurrentLength;
@@ -236,7 +254,8 @@ static u32  g_ErrorCode = 0;
 static bool g_bDiscInside = false;
 bool g_bStream = false;
 static bool g_bStopAtTrackEnd = false;
-static int  tc = 0;
+static int  finish_execute_command = 0;
+static int  finish_execute_read_command = 0;
 static int  dtk = 0;
 
 static u64 g_last_read_offset;
@@ -257,8 +276,8 @@ void UpdateInterrupts();
 void GenerateDIInterrupt(DIInterruptType _DVDInterrupt);
 
 void WriteImmediate(u32 value, u32 output_address, bool write_to_DIIMMBUF);
-DVDCommandResult ExecuteReadCommand(u64 DVD_offset, u32 output_address,
+DVDReadCommand ExecuteReadCommand(u64 DVD_offset, u32 output_address, u32 DVD_length, u32 output_length,
-	u32 DVD_length, u32 output_length, bool decrypt);
+                                  bool decrypt, DIInterruptType* interrupt_type, u64* ticks_until_completion);
 
 u64 SimulateDiscReadTime(u64 offset, u32 length);
 s64 CalculateRawDiscReadTime(u64 offset, s64 length);
@@ -274,6 +293,8 @@ void DoState(PointerWrap &p)
 	p.Do(m_DIIMMBUF);
 	p.DoPOD(m_DICFG);
 
+	p.Do(current_read_command);
+
 	p.Do(NextStart);
 	p.Do(AudioPos);
 	p.Do(NextLength);
@@ -291,7 +312,7 @@ void DoState(PointerWrap &p)
 	p.Do(g_bStopAtTrackEnd);
 }
 
-static void TransferComplete(u64 userdata, int cyclesLate)
+static void FinishExecuteCommand(u64 userdata, int cyclesLate)
 {
 	if (m_DICR.TSTART)
 	{
@@ -301,6 +322,30 @@ static void TransferComplete(u64 userdata, int cyclesLate)
 	}
 }
 
+static void FinishExecuteReadCommand(u64 userdata, int cyclesLate)
+{
+	if (!current_read_command.is_valid)
+	{
+		PanicAlertT("DVDInterface tried to execute non-existing command");
+	}
+	else
+	{
+		// Here is the actual disc reading
+		if (!DVDRead(current_read_command.DVD_offset, current_read_command.output_address,
+		             current_read_command.length, current_read_command.decrypt))
+		{
+			PanicAlertT("Can't read from DVD_Plugin - DVD-Interface: Fatal Error");
+		}
+	}
+
+	// The command is marked as invalid because it shouldn't be used again
+	current_read_command.is_valid = false;
+
+	// The final step is to notify the emulated software that the command has been executed
+	CoreTiming::ScheduleEvent_Immediate(current_read_command.callback_event_type,
+	                                    current_read_command.interrupt_type);
+}
+
 static u32 ProcessDTKSamples(short *tempPCM, u32 num_samples)
 {
 	u32 samples_processed = 0;
@@ -376,6 +421,8 @@ void Init()
 	m_DICFG.Hex       = 0;
 	m_DICFG.CONFIG    = 1; // Disable bootrom descrambler
 
+	current_read_command.is_valid = false;
+
 	AudioPos = 0;
 	NextStart = 0;
 	NextLength = 0;
@@ -393,7 +440,8 @@ void Init()
 	ejectDisc = CoreTiming::RegisterEvent("EjectDisc", EjectDiscCallback);
 	insertDisc = CoreTiming::RegisterEvent("InsertDisc", InsertDiscCallback);
 
-	tc = CoreTiming::RegisterEvent("TransferComplete", TransferComplete);
+	finish_execute_command = CoreTiming::RegisterEvent("FinishExecuteCommand", FinishExecuteCommand);
+	finish_execute_read_command = CoreTiming::RegisterEvent("FinishExecuteReadCommand", FinishExecuteReadCommand);
 	dtk = CoreTiming::RegisterEvent("StreamingTimer", DTKStreamingCallback);
 
 	CoreTiming::ScheduleEvent(0, dtk);
@@ -542,21 +590,8 @@ void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
 			m_DICR.Hex = val & 7;
 			if (m_DICR.TSTART)
 			{
-				DVDCommandResult result = ExecuteCommand(
+				ExecuteCommand(m_DICMDBUF[0].Hex, m_DICMDBUF[1].Hex, m_DICMDBUF[2].Hex,
-					m_DICMDBUF[0].Hex, m_DICMDBUF[1].Hex, m_DICMDBUF[2].Hex,
+				               m_DIMAR.Hex, m_DILENGTH.Hex, true, finish_execute_command);
-					m_DIMAR.Hex, m_DILENGTH.Hex, true);
-				if (SConfig::GetInstance().m_LocalCoreStartupParameter.bFastDiscSpeed)
-				{
-					// Make sure fast disc speed performs "instant" reads; in addition
-					// to being used to speed up games, fast disc speed is used as a
-					// workaround for crashes in Star Wars Rogue Leader.
-					TransferComplete(result.interrupt_type, 0);
-				}
-				else
-				{
-					// The transfer is finished after a delay
-					CoreTiming::ScheduleEvent((int)result.ticks_until_completion, tc, result.interrupt_type);
-				}
 			}
 		})
 	);
@@ -612,38 +647,51 @@ void WriteImmediate(u32 value, u32 output_address, bool write_to_DIIMMBUF)
 		Memory::Write_U32(value, output_address);
 }
 
-DVDCommandResult ExecuteReadCommand(u64 DVD_offset, u32 output_address,
+// If the returned DVDReadCommand has is_valid set to true,
-                                    u32 DVD_length, u32 output_length, bool decrypt)
+// FinishExecuteReadCommand must be used to finish executing it
+DVDReadCommand ExecuteReadCommand(u64 DVD_offset, u32 output_address, u32 DVD_length, u32 output_length,
+                                  bool decrypt, DIInterruptType* interrupt_type, u64* ticks_until_completion)
 {
+	DVDReadCommand command;
+
+	if (!g_bDiscInside)
+	{
+		g_ErrorCode = ERROR_NO_DISK | ERROR_COVER_H;
+		*interrupt_type = INT_DEINT;
+		command.is_valid = false;
+		return command;
+	}
+
 	if (DVD_length > output_length)
 	{
 		WARN_LOG(DVDINTERFACE, "Detected attempt to read more data from the DVD than fit inside the out buffer. Clamp.");
 		DVD_length = output_length;
 	}
 
-	DVDCommandResult result;
+	if (SConfig::GetInstance().m_LocalCoreStartupParameter.bFastDiscSpeed)
-	result.ticks_until_completion = SimulateDiscReadTime(DVD_offset, DVD_length);
+		*ticks_until_completion = 0;	// An optional hack to speed up loading times
+	else
+		*ticks_until_completion = SimulateDiscReadTime(DVD_offset, DVD_length);
 
-	if (!g_bDiscInside)
+	*interrupt_type = INT_TCINT;
-	{
+	command.is_valid = true;
-		g_ErrorCode = ERROR_NO_DISK | ERROR_COVER_H;
+	command.DVD_offset = DVD_offset;
-		result.interrupt_type = INT_DEINT;
+	command.output_address = output_address;
-		return result;
+	command.length = DVD_length;
-	}
+	command.decrypt = decrypt;
-
+	return command;
-	if (!DVDRead(DVD_offset, output_address, DVD_length, decrypt))
-		PanicAlertT("Can't read from DVD_Plugin - DVD-Interface: Fatal Error");
-
-	result.interrupt_type = INT_TCINT;
-	return result;
 }
 
-DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
+// When the command has finished executing, callback_event_type
-                                u32 output_address, u32 output_length, bool write_to_DIIMMBUF)
+// will be called using CoreTiming::ScheduleEvent,
+// with the userdata set to the interrupt type.
+void ExecuteCommand(u32 command_0, u32 command_1, u32 command_2, u32 output_address, u32 output_length,
+                    bool write_to_DIIMMBUF, int callback_event_type)
 {
-	DVDCommandResult result;
+	DIInterruptType interrupt_type = INT_TCINT;
-	result.interrupt_type = INT_TCINT;
+	u64 ticks_until_completion = SystemTimers::GetTicksPerSecond() / 15000;
-	result.ticks_until_completion = SystemTimers::GetTicksPerSecond() / 15000;
+	DVDReadCommand read_command;
+	read_command.is_valid = false;
 
 	bool GCAM = (SConfig::GetInstance().m_SIDevice[0] == SIDEVICE_AM_BASEBOARD) &&
 	            (SConfig::GetInstance().m_EXIDevice[2] == EXIDEVICE_AM_BASEBOARD);
@@ -688,19 +736,21 @@ DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
 	// Only seems to be used from WII_IPC, not through direct access
 	case DVDLowReadDiskID:
 		INFO_LOG(DVDINTERFACE, "DVDLowReadDiskID");
-		result = ExecuteReadCommand(0, output_address, 0x20, output_length, false);
+		read_command = ExecuteReadCommand(0, output_address, 0x20, output_length,
+		                                  false, &interrupt_type, &ticks_until_completion);
 		break;
 
 	// Only used from WII_IPC. This is the only read command that decrypts data
 	case DVDLowRead:
 		INFO_LOG(DVDINTERFACE, "DVDLowRead: DVDAddr: 0x%09" PRIx64 ", Size: 0x%x", (u64)command_2 << 2, command_1);
-		result = ExecuteReadCommand((u64)command_2 << 2, output_address, command_1, output_length, true);
+		read_command = ExecuteReadCommand((u64)command_2 << 2, output_address, command_1, output_length,
+		                                  true, &interrupt_type, &ticks_until_completion);
 		break;
 
 	// Probably only used by Wii
 	case DVDLowWaitForCoverClose:
 		INFO_LOG(DVDINTERFACE, "DVDLowWaitForCoverClose");
-		result.interrupt_type = (DIInterruptType)4; // ???
+		interrupt_type = (DIInterruptType)4; // ???
 		break;
 
 	// "Set Extension"...not sure what it does. GC only?
@@ -773,14 +823,15 @@ DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
 			(command_2 > 0x7ed40000 && command_2 < 0x7ed40008) ||
 			(((command_2 + command_1) > 0x7ed40000) && (command_2 + command_1) < 0x7ed40008)))
 		{
-			result = ExecuteReadCommand((u64)command_2 << 2, output_address, command_1, output_length, false);
+			read_command = ExecuteReadCommand((u64)command_2 << 2, output_address, command_1, output_length,
+			                                  false, &interrupt_type, &ticks_until_completion);
 		}
 		else
 		{
 			WARN_LOG(DVDINTERFACE, "DVDLowUnencryptedRead: trying to read out of bounds @ %09" PRIx64, (u64)command_2 << 2);
 			g_ErrorCode = ERROR_READY | ERROR_BLOCK_OOB;
 			// Should cause software to call DVDLowRequestError
-			result.interrupt_type = INT_BRKINT;
+			interrupt_type = INT_BRKINT;
 		}
 
 		break;
@@ -805,7 +856,7 @@ DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
 		// Does not work on retail discs/drives
 		// Retail games send this command to see if they are running on real retail hw
 		g_ErrorCode = ERROR_READY | ERROR_INV_CMD;
-		result.interrupt_type = INT_BRKINT;
+		interrupt_type = INT_BRKINT;
 		break;
 
 	// DMA Read from Disc. Only seems to be used through direct access, not WII_IPC
@@ -869,13 +920,15 @@ DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
 					}
 				}
 
-				result = ExecuteReadCommand(iDVDOffset, output_address, command_2, output_length, false);
+				read_command = ExecuteReadCommand(iDVDOffset, output_address, command_2, output_length,
+				                                  false, &interrupt_type, &ticks_until_completion);
 			}
 			break;
 
 		case 0x40: // Read DiscID
 			INFO_LOG(DVDINTERFACE, "Read DiscID %08x", Memory::Read_U32(output_address));
-			result = ExecuteReadCommand(0, output_address, 0x20, output_length, false);
+			read_command = ExecuteReadCommand(0, output_address, 0x20, output_length,
+			                                  false, &interrupt_type, &ticks_until_completion);
 			break;
 
 		default:
@@ -1210,7 +1263,23 @@ DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
 		break;
 	}
 
-	return result;
+	// The command will finish executing after a delay,
+	// to simulate the speed of a real disc drive
+	if (read_command.is_valid)
+	{
+		// We schedule a FinishExecuteReadCommand (which will call the actual callback
+		// once it's done) so that the data transfer isn't completed too early.
+		// Most games don't care about it, but if it's done wrong, Resident Evil 3
+		// plays some extra noise when playing the menu selection sound effect.
+		read_command.callback_event_type = callback_event_type;
+		read_command.interrupt_type = interrupt_type;
+		current_read_command = read_command;
+		CoreTiming::ScheduleEvent((int)ticks_until_completion, finish_execute_read_command);
+	}
+	else
+	{
+		CoreTiming::ScheduleEvent((int)ticks_until_completion, callback_event_type, interrupt_type);
+	}
 }
 
 // Simulates the timing aspects of reading data from a disc.

Source/Core/Core/HW/DVDInterface.h

@@ -85,12 +85,6 @@ enum DIInterruptType
 	INT_CVRINT = 3,
 };
 
-struct DVDCommandResult
-{
-	DIInterruptType interrupt_type;
-	u64 ticks_until_completion;
-};
-
 void Init();
 void Shutdown();
 void DoState(PointerWrap &p);
@@ -105,7 +99,7 @@ void ChangeDisc(const std::string& fileName);
 // DVD Access Functions
 bool DVDRead(u64 _iDVDOffset, u32 _iRamAddress, u32 _iLength, bool decrypt);
 extern bool g_bStream;
-DVDCommandResult ExecuteCommand(u32 command_0, u32 command_1, u32 command_2,
+void ExecuteCommand(u32 command_0, u32 command_1, u32 command_2, u32 output_address, u32 output_length,
-	u32 output_address, u32 output_length, bool write_to_DIIMMBUF);
+                    bool write_to_DIIMMBUF, int callback_event_type);
 
 } // end of namespace DVDInterface

Source/Core/Core/IPC_HLE/WII_IPC_HLE.cpp

@@ -85,7 +85,7 @@ static u64 last_reply_time;
 
 static const u64 ENQUEUE_REQUEST_FLAG = 0x100000000ULL;
 static const u64 ENQUEUE_ACKNOWLEDGEMENT_FLAG = 0x200000000ULL;
-static void EnqueueEventCallback(u64 userdata, int)
+static void EnqueueEvent(u64 userdata, int cycles_late = 0)
 {
 	if (userdata & ENQUEUE_ACKNOWLEDGEMENT_FLAG)
 	{
@@ -144,7 +144,7 @@ void Init()
 	g_DeviceMap[i] = new CWII_IPC_HLE_Device_stub(i, "/dev/usb/oh1"); i++;
 	g_DeviceMap[i] = new IWII_IPC_HLE_Device(i, "_Unimplemented_Device_"); i++;
 
-	event_enqueue = CoreTiming::RegisterEvent("IPCEvent", EnqueueEventCallback);
+	event_enqueue = CoreTiming::RegisterEvent("IPCEvent", EnqueueEvent);
 }
 
 void Reset(bool _bHard)
@@ -563,6 +563,11 @@ void EnqueueReply_Threadsafe(u32 address, int cycles_in_future)
 	CoreTiming::ScheduleEvent_Threadsafe(cycles_in_future, event_enqueue, address);
 }
 
+void EnqueueReply_Immediate(u32 address)
+{
+	EnqueueEvent(address);
+}
+
 void EnqueueCommandAcknowledgement(u32 address, int cycles_in_future)
 {
 	CoreTiming::ScheduleEvent(cycles_in_future, event_enqueue,

Source/Core/Core/IPC_HLE/WII_IPC_HLE.h

@@ -80,6 +80,7 @@ void ExecuteCommand(u32 _Address);
 void EnqueueRequest(u32 address);
 void EnqueueReply(u32 address, int cycles_in_future = 0);
 void EnqueueReply_Threadsafe(u32 address, int cycles_in_future = 0);
+void EnqueueReply_Immediate(u32 address);
 void EnqueueCommandAcknowledgement(u32 _Address, int cycles_in_future = 0);
 
 } // end of namespace WII_IPC_HLE_Interface

Source/Core/Core/IPC_HLE/WII_IPC_HLE_Device_DI.cpp

@@ -9,6 +9,7 @@
 #include "Common/Logging/LogManager.h"
 
 #include "Core/ConfigManager.h"
+#include "Core/CoreTiming.h"
 #include "Core/VolumeHandler.h"
 #include "Core/HW/DVDInterface.h"
 #include "Core/HW/Memmap.h"
@@ -17,14 +18,38 @@
 #include "Core/IPC_HLE/WII_IPC_HLE.h"
 #include "Core/IPC_HLE/WII_IPC_HLE_Device_DI.h"
 
-using namespace DVDInterface;
+static CWII_IPC_HLE_Device_di* g_di_pointer;
+static int ioctl_callback;
 
-CWII_IPC_HLE_Device_di::CWII_IPC_HLE_Device_di(u32 _DeviceID, const std::string& _rDeviceName )
+static void IOCtlCallback(u64 userdata, int cycles_late)
+{
+	if (g_di_pointer != nullptr)
+		g_di_pointer->FinishIOCtl((DVDInterface::DIInterruptType)userdata);
+
+	// If g_di_pointer == nullptr, IOS was probably shut down,
+	// so the command shouldn't be completed
+}
+
+CWII_IPC_HLE_Device_di::CWII_IPC_HLE_Device_di(u32 _DeviceID, const std::string& _rDeviceName)
 	: IWII_IPC_HLE_Device(_DeviceID, _rDeviceName)
-{}
+{
+	if (g_di_pointer == nullptr)
+		ERROR_LOG(WII_IPC_DVD, "Trying to run two DI devices at once. IOCtl may not behave as expected.");
+
+	g_di_pointer = this;
+	ioctl_callback = CoreTiming::RegisterEvent("IOCtlCallbackDI", IOCtlCallback);
+}
 
 CWII_IPC_HLE_Device_di::~CWII_IPC_HLE_Device_di()
-{}
+{
+	g_di_pointer = nullptr;
+}
+
+void CWII_IPC_HLE_Device_di::DoState(PointerWrap& p)
+{
+	DoStateShared(p);
+	p.Do(m_commands_to_execute);
+}
 
 IPCCommandResult CWII_IPC_HLE_Device_di::Open(u32 _CommandAddress, u32 _Mode)
 {
@@ -43,10 +68,29 @@ IPCCommandResult CWII_IPC_HLE_Device_di::Close(u32 _CommandAddress, bool _bForce
 
 IPCCommandResult CWII_IPC_HLE_Device_di::IOCtl(u32 _CommandAddress)
 {
-	u32 BufferIn = Memory::Read_U32(_CommandAddress + 0x10);
+	// DI IOCtls are handled in a special way by Dolphin
-	u32 BufferInSize = Memory::Read_U32(_CommandAddress + 0x14);
+	// compared to other WII_IPC_HLE functions.
-	u32 BufferOut = Memory::Read_U32(_CommandAddress + 0x18);
+	// This is a wrapper around DVDInterface's ExecuteCommand,
-	u32 BufferOutSize = Memory::Read_U32(_CommandAddress + 0x1C);
+	// which will execute commands more or less asynchronously.
+	// Only one command can be executed at a time, so commands
+	// are queued until DVDInterface is ready to handle them.
+
+	bool ready_to_execute = m_commands_to_execute.empty();
+	m_commands_to_execute.push_back(_CommandAddress);
+	if (ready_to_execute)
+		StartIOCtl(_CommandAddress);
+
+	// DVDInterface handles the timing, and we handle the reply,
+	// so WII_IPC_HLE shouldn't do any of that.
+	return IPC_NO_REPLY;
+}
+
+void CWII_IPC_HLE_Device_di::StartIOCtl(u32 command_address)
+{
+	u32 BufferIn = Memory::Read_U32(command_address + 0x10);
+	u32 BufferInSize = Memory::Read_U32(command_address + 0x14);
+	u32 BufferOut = Memory::Read_U32(command_address + 0x18);
+	u32 BufferOutSize = Memory::Read_U32(command_address + 0x1C);
 
 	u32 command_0 = Memory::Read_U32(BufferIn);
 	u32 command_1 = Memory::Read_U32(BufferIn + 4);
@@ -63,14 +107,38 @@ IPCCommandResult CWII_IPC_HLE_Device_di::IOCtl(u32 _CommandAddress)
 		Memory::Memset(BufferOut, 0, BufferOutSize);
 	}
 
-	DVDCommandResult result = ExecuteCommand(command_0, command_1, command_2,
+	// DVDInterface's ExecuteCommand handles most of the work.
-	                                         BufferOut, BufferOutSize, false);
+	// The IOCtl callback is used to generate a reply afterwards.
-	Memory::Write_U32(result.interrupt_type, _CommandAddress + 0x4);
+	DVDInterface::ExecuteCommand(command_0, command_1, command_2, BufferOut, BufferOutSize,
+	                             false, ioctl_callback);
+}
 
-	if (SConfig::GetInstance().m_LocalCoreStartupParameter.bFastDiscSpeed)
+void CWII_IPC_HLE_Device_di::FinishIOCtl(DVDInterface::DIInterruptType interrupt_type)
-		result.ticks_until_completion = 0;	// An optional hack to speed up loading times
+{
+	if (m_commands_to_execute.empty())
+	{
+		PanicAlertT("WII_IPC_HLE_Device_DI tried to reply to non-existing command");
+		return;
+	}
 
-	return { true, result.ticks_until_completion };
+	// This command has been executed, so it's removed from the queue
+	u32 command_address = m_commands_to_execute.front();
+	m_commands_to_execute.pop_front();
+
+	// The DI interrupt type is used as a return value
+	Memory::Write_U32(interrupt_type, command_address + 4);
+
+	// The original hardware overwrites the command type with the async reply type.
+	Memory::Write_U32(IPC_REP_ASYNC, command_address);
+	// IOS also seems to write back the command that was responded to in the FD field.
+	Memory::Write_U32(Memory::Read_U32(command_address), command_address + 8);
+	// Generate a reply to the IPC command
+	WII_IPC_HLE_Interface::EnqueueReply_Immediate(command_address);
+
+	// DVDInterface is now ready to execute another command,
+	// so we start executing a command from the queue if there is one
+	if (!m_commands_to_execute.empty())
+		StartIOCtl(m_commands_to_execute.front());
 }
 
 IPCCommandResult CWII_IPC_HLE_Device_di::IOCtlV(u32 _CommandAddress)
@@ -88,7 +156,7 @@ IPCCommandResult CWII_IPC_HLE_Device_di::IOCtlV(u32 _CommandAddress)
 	u32 ReturnValue = 0;
 	switch (CommandBuffer.Parameter)
 	{
-	case DVDLowOpenPartition:
+	case DVDInterface::DVDLowOpenPartition:
 		{
 			_dbg_assert_msg_(WII_IPC_DVD, CommandBuffer.InBuffer[1].m_Address == 0, "DVDLowOpenPartition with ticket");
 			_dbg_assert_msg_(WII_IPC_DVD, CommandBuffer.InBuffer[2].m_Address == 0, "DVDLowOpenPartition with cert chain");

Source/Core/Core/IPC_HLE/WII_IPC_HLE_Device_DI.h

@@ -4,14 +4,10 @@
 
 #pragma once
 
+#include <deque>
+#include "Core/HW/DVDInterface.h"
 #include "Core/IPC_HLE/WII_IPC_HLE_Device.h"
 
-namespace DiscIO
-{
-	class IVolume;
-	class IFileSystem;
-}
-
 class CWII_IPC_HLE_Device_di : public IWII_IPC_HLE_Device
 {
 public:
@@ -20,9 +16,18 @@ public:
 
 	virtual ~CWII_IPC_HLE_Device_di();
 
+	void DoState(PointerWrap& p) override;
+
 	IPCCommandResult Open(u32 _CommandAddress, u32 _Mode) override;
 	IPCCommandResult Close(u32 _CommandAddress, bool _bForce) override;
 
 	IPCCommandResult IOCtl(u32 _CommandAddress) override;
 	IPCCommandResult IOCtlV(u32 _CommandAddress) override;
+
+	void FinishIOCtl(DVDInterface::DIInterruptType interrupt_type);
+private:
+
+	void StartIOCtl(u32 command_address);
+
+	std::deque<u32> m_commands_to_execute;
 };

Source/Core/Core/State.cpp

@@ -64,7 +64,7 @@ static Common::Event g_compressAndDumpStateSyncEvent;
 static std::thread g_save_thread;
 
 // Don't forget to increase this after doing changes on the savestate system
-static const u32 STATE_VERSION = 39;
+static const u32 STATE_VERSION = 40;
 
 enum
 {