From 111694051e4f2f22a8da02c7acaaecfed623703c Mon Sep 17 00:00:00 2001
From: "SND\\shalma_cp" <SND\shalma_cp@e17a0e51-4ae3-4d35-97c3-1a29b211df97>
Date: Thu, 16 Sep 2010 00:48:29 +0000
Subject: Rebel Assault 2 - MDEC: Fix DMA timing (byte ptrs) - GPU: Fix DMA
 timing (word sizes, chain counting)

git-svn-id: https://pcsxr.svn.codeplex.com/svn/pcsxr@57226 e17a0e51-4ae3-4d35-97c3-1a29b211df97
---
 libpcsxcore/gpu.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

(limited to 'libpcsxcore/gpu.c')

diff --git a/libpcsxcore/gpu.c b/libpcsxcore/gpu.c
index 4388cfee..5b2568b4 100644
--- a/libpcsxcore/gpu.c
+++ b/libpcsxcore/gpu.c
@@ -55,21 +55,26 @@ static inline boolean CheckForEndlessLoop(u32 laddr) {
 }
 
 static u32 gpuDmaChainSize(u32 addr) {
-	unsigned int DMACommandCounter = 0;
-	u32 size = 0;
+	u32 size;
+	u32 DMACommandCounter = 0;
 
 	lUsedAddr[0] = lUsedAddr[1] = lUsedAddr[2] = 0xffffff;
 
+	// initial linked list ptr (bytes)
+	size = 4;
+
 	do {
 		addr &= 0x1ffffc;
 
 		if (DMACommandCounter++ > 2000000) break;
 		if (CheckForEndlessLoop(addr)) break;
 
-		size += 4;
-		size += psxMu8(addr + 3);
+		// # 32-bit blocks to transfer
+		size += psxMu8( addr + 3 ) * 4;
 
-		addr = psxMu32(addr & ~0x3) & 0xffffff;
+		// next 32-bit pointer
+		addr = psxMu32( addr & ~0x3 ) & 0xffffff;
+		size += 4;
 	} while (addr != 0xffffff);
 
 	return size;
@@ -140,11 +145,13 @@ void psxDma2(u32 madr, u32 bcr, u32 chcr) { // GPU
 #endif
 				break;
 			}
+			// BA blocks * BS words (word = 32-bits)
 			size = (bcr >> 16) * (bcr & 0xffff);
 			GPU_readDataMem(ptr, size);
 			psxCpu->Clear(madr, size);
 
-			GPUDMA_INT(size / 4);
+			// already 32-bit word size ((size * 4) / 4)
+			GPUDMA_INT(size);
 			return;
 
 		case 0x01000201: // mem2vram
@@ -158,10 +165,12 @@ void psxDma2(u32 madr, u32 bcr, u32 chcr) { // GPU
 #endif
 				break;
 			}
+			// BA blocks * BS words (word = 32-bits)
 			size = (bcr >> 16) * (bcr & 0xffff);
 			GPU_writeDataMem(ptr, size);
 
-			GPUDMA_INT(size / 4);
+			// already 32-bit word size ((size * 4) / 4)
+			GPUDMA_INT(size);
 			return;
 
 		case 0x01000401: // dma chain
@@ -170,7 +179,11 @@ void psxDma2(u32 madr, u32 bcr, u32 chcr) { // GPU
 #endif
 			GPU_dmaChain((u32 *)psxM, madr & 0x1fffff);
 
-			size = gpuDmaChainSize(madr);
+			//size = gpuDmaChainSize(madr);
+
+			// HACK: Rebel Assault 2 wants longer time (stage 6)
+			size = gpuDmaChainSize(madr) * 1.5;
+			
 			GPUDMA_INT(size / 4);
 			return;
 
-- 
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