From f929d79473ad62ce7e9d3a5f9e223a6574b13bc1 Mon Sep 17 00:00:00 2001
From: refractionpcsx2 <refraction@gmail.com>
Date: Sun, 29 Nov 2020 19:23:27 +0000
Subject: [PATCH] SPU2: Delay DMA Reads to prevent overrun

Savestate bump
---
 pcsx2/SPU2/Dma.cpp     | 20 +++++++++++++-------
 pcsx2/SPU2/defs.h      |  4 ++++
 pcsx2/SPU2/spu2sys.cpp |  6 ++++++
 pcsx2/SaveState.h      |  2 +-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/pcsx2/SPU2/Dma.cpp b/pcsx2/SPU2/Dma.cpp
index ad4e713a6b..32ca6bc5ec 100644
--- a/pcsx2/SPU2/Dma.cpp
+++ b/pcsx2/SPU2/Dma.cpp
@@ -334,11 +334,9 @@ void V_Core::PlainDMAWrite(u16* pMem, u32 size)
 	TADR = MADR + (size << 1);
 }
 
-void V_Core::DoDMAread(u16* pMem, u32 size)
+void V_Core::FinishDMAread()
 {
-	TSA &= 0xfffff;
-
-	u32 buff1end = TSA + size;
+	u32 buff1end = TSA + ReadSize;
 	u32 buff2end = 0;
 	if (buff1end > 0x100000)
 	{
@@ -347,8 +345,7 @@ void V_Core::DoDMAread(u16* pMem, u32 size)
 	}
 
 	const u32 buff1size = (buff1end - TSA);
-	memcpy(pMem, GetMemPtr(TSA), buff1size * 2);
-
+	memcpy(DMARPtr, GetMemPtr(TSA), buff1size * 2);
 	// Note on TSA's position after our copy finishes:
 	// IRQA should be measured by the end of the writepos+0x20.  But the TDA
 	// should be written back at the precise endpoint of the xfer.
@@ -360,7 +357,7 @@ void V_Core::DoDMAread(u16* pMem, u32 size)
 		// second branch needs cleared:
 		// It starts at the beginning of memory and moves forward to buff2end
 
-		memcpy(&pMem[buff1size], GetMemPtr(0), buff2end * 2);
+		memcpy(&DMARPtr[buff1size], GetMemPtr(0), buff2end * 2);
 
 		TDA = (buff2end + 0x20) & 0xfffff;
 
@@ -396,6 +393,15 @@ void V_Core::DoDMAread(u16* pMem, u32 size)
 	}
 
 	TSA = TDA;
+	IsDMARead = false;
+}
+
+void V_Core::DoDMAread(u16* pMem, u32 size)
+{
+	TSA &= 0xfffff;
+	DMARPtr = pMem;
+	ReadSize = size;
+	IsDMARead = true;
 
 	DMAICounter = size;
 	Regs.STATX &= ~0x80;
diff --git a/pcsx2/SPU2/defs.h b/pcsx2/SPU2/defs.h
index c620a4b2b3..f13f102aa2 100644
--- a/pcsx2/SPU2/defs.h
+++ b/pcsx2/SPU2/defs.h
@@ -437,6 +437,9 @@ struct V_Core
 
 	// old dma only
 	u16* DMAPtr;
+	u16* DMARPtr; // Mem pointer for DMA Reads
+	u32 ReadSize;
+	bool IsDMARead;
 	u32 MADR;
 	u32 TADR;
 
@@ -525,6 +528,7 @@ struct V_Core
 	// old dma only
 	void DoDMAwrite(u16* pMem, u32 size);
 	void DoDMAread(u16* pMem, u32 size);
+	void FinishDMAread();
 
 	void AutoDMAReadBuffer(int mode);
 	void StartADMAWrite(u16* pMem, u32 sz);
diff --git a/pcsx2/SPU2/spu2sys.cpp b/pcsx2/SPU2/spu2sys.cpp
index d66ecc7d63..75de7ad615 100644
--- a/pcsx2/SPU2/spu2sys.cpp
+++ b/pcsx2/SPU2/spu2sys.cpp
@@ -427,6 +427,9 @@ __forceinline void TimeUpdate(u32 cClocks)
 			Cores[0].DMAICounter -= TickInterval;
 			if (Cores[0].DMAICounter <= 0)
 			{
+				if (Cores[0].IsDMARead)
+					Cores[0].FinishDMAread();
+
 				//ConLog("counter set and callback!\n");
 				Cores[0].MADR = Cores[0].TADR;
 				Cores[0].DMAICounter = 0;
@@ -447,6 +450,9 @@ __forceinline void TimeUpdate(u32 cClocks)
 			Cores[1].DMAICounter -= TickInterval;
 			if (Cores[1].DMAICounter <= 0)
 			{
+				if (Cores[1].IsDMARead)
+					Cores[1].FinishDMAread();
+
 				Cores[1].MADR = Cores[1].TADR;
 				Cores[1].DMAICounter = 0;
 				//ConLog( "* SPU2 > DMA 7 Callback!  %d\n", Cycles );
diff --git a/pcsx2/SaveState.h b/pcsx2/SaveState.h
index f0356680c4..d817ff642d 100644
--- a/pcsx2/SaveState.h
+++ b/pcsx2/SaveState.h
@@ -24,7 +24,7 @@
 //  the lower 16 bit value.  IF the change is breaking of all compatibility with old
 //  states, increment the upper 16 bit value, and clear the lower 16 bits to 0.
 
-static const u32 g_SaveVersion = (0x9A10 << 16) | 0x0000;
+static const u32 g_SaveVersion = (0x9A11 << 16) | 0x0000;
 
 // this function is meant to be used in the place of GSfreeze, and provides a safe layer
 // between the GS saving function and the MTGS's needs. :)