From c6d8b52d2691d2a203f5a9cda7d4c9a72b871712 Mon Sep 17 00:00:00 2001
From: Gregory Hainaut <gregory.hainaut@gmail.com>
Date: Thu, 1 May 2014 16:35:24 +0200
Subject: [PATCH] pcsx2: try to ensure better sync with FIFO read call

First wait will ensure correctness of GS register.
2nd wait will ensure that the GS fifo read call is finished

(If I understand MTGS correctly)
---
 pcsx2/FiFo.cpp     | 3 ++-
 pcsx2/MTGS.cpp     | 2 ++
 pcsx2/Vif1_Dma.cpp | 3 ++-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/pcsx2/FiFo.cpp b/pcsx2/FiFo.cpp
index dc417af315..ed658bc0eb 100644
--- a/pcsx2/FiFo.cpp
+++ b/pcsx2/FiFo.cpp
@@ -50,8 +50,9 @@ void __fastcall ReadFIFO_VIF1(mem128_t* out)
 			DevCon.Warning("Warning! GS Download size < FIFO count!");
 		}
 		if (vif1Regs.stat.FQC > 0) {
-			GetMTGS().SendPointerPacket(GS_RINGTYPE_READ_FIFO1, 0, out);
 			GetMTGS().WaitGS();
+			GetMTGS().SendPointerPacket(GS_RINGTYPE_READ_FIFO1, 0, out);
+			GetMTGS().WaitGS(false); // wait without reg sync
 			vif1.GSLastDownloadSize--;
 			GUNIT_LOG("ReadFIFO_VIF1");
 			if (vif1.GSLastDownloadSize <= 16)
diff --git a/pcsx2/MTGS.cpp b/pcsx2/MTGS.cpp
index ba1c8e9d96..abafa728a4 100644
--- a/pcsx2/MTGS.cpp
+++ b/pcsx2/MTGS.cpp
@@ -496,10 +496,12 @@ void SysMtgsThread::ExecuteTaskInThread()
 						break;
 
 						case GS_RINGTYPE_READ_FIFO1:
+							MTGS_LOG( "(MTGS Packet Read) ringtype=Fifo1" );
 							GSreadFIFO( (u64*)tag.data[1]);
 						break;
 
 						case GS_RINGTYPE_READ_FIFO2:
+							MTGS_LOG( "(MTGS Packet Read) ringtype=Fifo2, size=%d", tag.data[0] );
 							GSreadFIFO2( (u64*)tag.data[1], tag.data[0]);
 						break;
 
diff --git a/pcsx2/Vif1_Dma.cpp b/pcsx2/Vif1_Dma.cpp
index 8f3157bc2d..af3fdb0238 100644
--- a/pcsx2/Vif1_Dma.cpp
+++ b/pcsx2/Vif1_Dma.cpp
@@ -67,8 +67,9 @@ void vif1TransferToMemory()
 		pxAssert(p3.isDone() || !p3.gifTag.isValid);
 	}
 
-	GetMTGS().SendPointerPacket(GS_RINGTYPE_READ_FIFO2, size, pMem);
 	GetMTGS().WaitGS();
+	GetMTGS().SendPointerPacket(GS_RINGTYPE_READ_FIFO2, size, pMem);
+	GetMTGS().WaitGS(false); // wait without reg sync
 	pMem += size;
 
 	if(pMem < pMemEnd) {