From 4497532edb6e738b2324972bc924db65c81f6c37 Mon Sep 17 00:00:00 2001
From: refractionpcsx2 <refraction@gmail.com>
Date: Sat, 23 Jan 2021 06:20:14 +0000
Subject: [PATCH] SPU2: Improve ADMA behaviour/timing

---
 pcsx2/SPU2/Dma.cpp       | 23 +++++++++++++++--------
 pcsx2/SPU2/ReadInput.cpp | 38 +++++++++++---------------------------
 pcsx2/SPU2/spu2sys.cpp   |  6 +++---
 3 files changed, 29 insertions(+), 38 deletions(-)

diff --git a/pcsx2/SPU2/Dma.cpp b/pcsx2/SPU2/Dma.cpp
index 99e7aecbd9..39b7967a78 100644
--- a/pcsx2/SPU2/Dma.cpp
+++ b/pcsx2/SPU2/Dma.cpp
@@ -97,8 +97,10 @@ void V_Core::LogAutoDMA(FILE* fp)
 
 void V_Core::AutoDMAReadBuffer(int mode) //mode: 0= split stereo; 1 = do not split stereo
 {
-	int spos = ((InputPosRead + 0xff) & 0x100); //starting position of the free buffer
+	int spos = ActiveTSA & 0x100;// ((InputPosRead + 0xff) & 0x100); //starting position of the free buffer
 
+	if (spos == (OutPos & 0x100))
+		return;
 	LogAutoDMA(Index ? ADMA7LogFile : ADMA4LogFile);
 
 	// HACKFIX!! DMAPtr can be invalid after a savestate load, so the savestate just forces it
@@ -129,6 +131,9 @@ void V_Core::AutoDMAReadBuffer(int mode) //mode: 0= split stereo; 1 = do not spl
 		MADR += 0x200;
 		InputDataLeft -= 0x100;
 		InputDataProgress += 0x100;
+		ActiveTSA += 0x100;
+		ActiveTSA &= ~0x200;
+		TSA = ActiveTSA;
 	}
 	// See ReadInput at mixer.cpp for explanation on the commented out lines
 	//
@@ -155,6 +160,7 @@ void V_Core::StartADMAWrite(u16* pMem, u32 sz)
 	else if (size >= 512)
 	{
 		InputDataLeft = size;
+		AutoDMACtrl &= 3;
 		if (AdmaInProgress == 0)
 		{
 #ifdef PCM24_S1_INTERLEAVE
@@ -172,15 +178,18 @@ void V_Core::StartADMAWrite(u16* pMem, u32 sz)
 
 			AutoDMAReadBuffer(0);
 #endif
+
+			AdmaInProgress = 1;
+
 			// Klonoa 2
-			if (size == 512)
+			if (!InputDataLeft)
 			{
 				DMAICounter = size * 4;
 				LastClock = *cyclePtr;
+				AdmaInProgress = 0;
+				AutoDMACtrl |= ~3;
 			}
 		}
-
-		AdmaInProgress = 1;
 	}
 	else
 	{
@@ -357,8 +366,6 @@ void V_Core::FinishDMAwrite()
 
 void V_Core::FinishDMAread()
 {
-	if (ActiveTSA != TSA)
-		ConLog("Read WTF TSA %x Active %x\n", TSA, ActiveTSA);
 	u32 buff1end = ActiveTSA + std::min(ReadSize, (u32)0x100 + std::abs(DMAICounter / 4));
 	u32 start = ActiveTSA;
 	u32 buff2end = 0;
@@ -520,7 +527,7 @@ void V_Core::DoDMAwrite(u16* pMem, u32 size)
 	else
 	{
 		PlainDMAWrite(pMem, size);
+		Regs.STATX &= ~0x80;
+		Regs.STATX |= 0x400;
 	}
-	Regs.STATX &= ~0x80;
-	Regs.STATX |= 0x400;
 }
diff --git a/pcsx2/SPU2/ReadInput.cpp b/pcsx2/SPU2/ReadInput.cpp
index 3fb6dee0bb..bdb5b2fe62 100644
--- a/pcsx2/SPU2/ReadInput.cpp
+++ b/pcsx2/SPU2/ReadInput.cpp
@@ -123,7 +123,7 @@ StereoOut32 V_Core::ReadInput()
 	if ((Index != 1) || ((PlayMode & 2) == 0))
 	{
 		for (int i = 0; i < 2; i++)
-			if (Cores[i].IRQEnable && 0x2000 + (Index << 10) + InputPosRead == (Cores[i].IRQA & 0xfffffdff))
+			if (Cores[i].IRQEnable && 0x2000 + (Index << 10) + OutPos == (Cores[i].IRQA & 0xfffffdff))
 				SetIrqCall(i);
 
 		//retval = StereoOut32(
@@ -131,8 +131,8 @@ StereoOut32 V_Core::ReadInput()
 		//	(s32)ADMATempBuffer[InputPosRead+0x200]
 		//);
 		retval = StereoOut32(
-			(s32)(*GetMemPtr(0x2000 + (Index << 10) + InputPosRead)),
-			(s32)(*GetMemPtr(0x2200 + (Index << 10) + InputPosRead)));
+			(s32)(*GetMemPtr(0x2000 + (Index << 10) + OutPos)),
+			(s32)(*GetMemPtr(0x2200 + (Index << 10) + OutPos)));
 	}
 
 #ifdef PCSX2_DEVBUILD
@@ -142,21 +142,19 @@ StereoOut32 V_Core::ReadInput()
 
 	InputPosRead++;
 
-	if ((AutoDMACtrl & (Index + 1)) && (InputPosRead == 0x100 || InputPosRead == 0x200))
+	if ((OutPos == 0xFF || OutPos == 0x1FF))
 	{
-		AdmaInProgress = 0;
 		if (InputDataLeft >= 0x200)
 		{
 			//u8 k=InputDataLeft>=InputDataProgress;
-
+			int oldOutPos = OutPos;
+			OutPos = (OutPos + 1) & 0x1FF;
 			AutoDMAReadBuffer(0);
-
+			OutPos = oldOutPos;
 			AdmaInProgress = 1;
-			ActiveTSA = (Index << 10) + InputPosRead;
-			TSA = ActiveTSA;
 			if (InputDataLeft < 0x200)
 			{
-				if((AutoDMACtrl & (Index + 1)))
+				if ((AutoDMACtrl & (Index + 1)))
 					AutoDMACtrl |= ~3;
 
 				if (IsDevBuild)
@@ -168,24 +166,10 @@ StereoOut32 V_Core::ReadInput()
 							ConLog("WARNING: adma buffer didn't finish with a whole block!!\n");
 					}
 				}
-
+				AdmaInProgress = 0;
 				InputDataLeft = 0;
-				// Hack, kinda. We call the interrupt early here, since PCSX2 doesn't like them delayed.
-				//DMAICounter   = 1;
-				if (Index == 0)
-				{
-					if (!SPU2_dummy_callback)
-						spu2DMA4Irq();
-					else
-						SPU2interruptDMA4();
-				}
-				else
-				{
-					if (!SPU2_dummy_callback)
-						spu2DMA7Irq();
-					else
-						SPU2interruptDMA7();
-				}
+				DMAICounter = 0x200 * 4;
+				LastClock = *cyclePtr;
 			}
 		}
 	}
diff --git a/pcsx2/SPU2/spu2sys.cpp b/pcsx2/SPU2/spu2sys.cpp
index 4d81b1d12d..095d7fc995 100644
--- a/pcsx2/SPU2/spu2sys.cpp
+++ b/pcsx2/SPU2/spu2sys.cpp
@@ -1522,11 +1522,11 @@ static void __fastcall RegWrite_Core(u16 value)
 				return;
 			}
 			thiscore.AutoDMACtrl = value;
-			if (value == 0 && thiscore.AdmaInProgress && (thiscore.Regs.STATX & 0x400))
+			if (value == 0 && thiscore.AdmaInProgress)
 			{
+				// Kill the current transfer so it doesn't continue
 				thiscore.AdmaInProgress = 0;
-				thiscore.Regs.STATX &= ~0x400; // Set DMA as not busy transferring
-				// No need to end the DMA here, the IOP seems to handle that
+				thiscore.InputDataLeft = 0;
 			}
 			break;