From 31ca0a1d0b955752c6660a66222286206bad37d2 Mon Sep 17 00:00:00 2001
From: Jean-Philip Desjardins <jean-philip.desjardins@polymtl.ca>
Date: Sun, 18 Sep 2016 17:34:41 -0400
Subject: [PATCH] Simulate data being available in VIF1 FIFO when FDR is set.

---
 Source/ee/Vif.cpp | 9 +++++++++
 Source/ee/Vif.h   | 8 +++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Source/ee/Vif.cpp b/Source/ee/Vif.cpp
index ba4516c3..d82d1e10 100644
--- a/Source/ee/Vif.cpp
+++ b/Source/ee/Vif.cpp
@@ -82,6 +82,12 @@ uint32 CVif::GetRegister(uint32 address)
 	case VIF0_STAT:
 	case VIF1_STAT:
 		result = m_STAT;
+		if(m_STAT.nFDR != 0)
+		{
+			//When FDR is set, it usually means the game is trying to
+			//read data from GS and that FIFO has some data in it
+			result |= (0x10 << 24);
+		}
 		break;
 	case VIF0_MARK:
 	case VIF1_MARK:
@@ -139,6 +145,9 @@ void CVif::SetRegister(uint32 address, uint32 value)
 	{
 		switch(address)
 		{
+		case VIF1_STAT:
+			m_STAT.nFDR = ((value & STAT_FDR) != 0) ? 1 : 0;
+			break;
 		case VIF0_FBRST:
 		case VIF1_FBRST:
 			if(value & FBRST_RST)
diff --git a/Source/ee/Vif.h b/Source/ee/Vif.h
index b34836a7..b7c4dc8f 100644
--- a/Source/ee/Vif.h
+++ b/Source/ee/Vif.h
@@ -74,6 +74,11 @@ protected:
 		FBRST_STC = 0x08
 	};
 
+	enum
+	{
+		STAT_FDR = 0x00800000,
+	};
+
 	enum
 	{
 		FIFO_SIZE = 0x100
@@ -129,7 +134,8 @@ protected:
 		unsigned int	nINT		: 1;
 		unsigned int	nER0		: 1;
 		unsigned int	nER1		: 1;
-		unsigned int	nReserved2	: 10;
+		unsigned int	nReserved2	: 9;
+		unsigned int	nFDR		: 1;  //VIF1 only
 		unsigned int	nFQC		: 4;
 		unsigned int	nReserved3	: 4;
 	};