From 1f77c86322bf6567909da192fdbf6c28c0596a13 Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Wed, 29 Jun 2011 19:55:38 +0300
Subject: [PATCH 1/1] dma: more accurate ICR register handling

based on tests on ther real thing.
---
 libpcsxcore/new_dynarec/pcsxmem.c | 11 +++++++++--
 libpcsxcore/psxhw.c               | 14 ++++++++++++--
 libpcsxcore/psxhw.h               | 20 +++++++++++++++-----
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/libpcsxcore/new_dynarec/pcsxmem.c b/libpcsxcore/new_dynarec/pcsxmem.c
index 8b6714bf..601a6ee8 100644
--- a/libpcsxcore/new_dynarec/pcsxmem.c
+++ b/libpcsxcore/new_dynarec/pcsxmem.c
@@ -179,8 +179,15 @@ static void io_write_imask32(u32 value)
 
 static void io_write_dma_icr32(u32 value)
 {
-	u32 tmp = ~value & HW_DMA_ICR;
-	HW_DMA_ICR = ((tmp ^ value) & 0xffffff) ^ tmp;
+	u32 tmp = value & 0x00ff803f;
+	tmp |= (SWAPu32(HW_DMA_ICR) & ~value) & 0x7f000000;
+	if ((tmp & HW_DMA_ICR_GLOBAL_ENABLE && tmp & 0x7f000000)
+	    || tmp & HW_DMA_ICR_BUS_ERROR) {
+		if (!(SWAPu32(HW_DMA_ICR) & HW_DMA_ICR_IRQ_SENT))
+			psxHu32ref(0x1070) |= SWAP32(8);
+		tmp |= HW_DMA_ICR_IRQ_SENT;
+	}
+	HW_DMA_ICR = SWAPu32(tmp);
 }
 
 #define make_dma_func(n) \
diff --git a/libpcsxcore/psxhw.c b/libpcsxcore/psxhw.c
index 8069c07a..54e03f64 100644
--- a/libpcsxcore/psxhw.c
+++ b/libpcsxcore/psxhw.c
@@ -25,6 +25,9 @@
 #include "mdec.h"
 #include "cdrom.h"
 
+//#undef PSXHW_LOG
+//#define PSXHW_LOG printf
+
 void psxHwReset() {
 	if (Config.Sio) psxHu32ref(0x1070) |= SWAP32(0x80);
 	if (Config.SpuIrq) psxHu32ref(0x1070) |= SWAP32(0x200);
@@ -658,8 +661,15 @@ void psxHwWrite32(u32 add, u32 value) {
 			PSXHW_LOG("DMA ICR 32bit write %x\n", value);
 #endif
 		{
-			u32 tmp = (~value) & SWAPu32(HW_DMA_ICR);
-			HW_DMA_ICR = SWAPu32(((tmp ^ value) & 0xffffff) ^ tmp);
+			u32 tmp = value & 0x00ff803f;
+			tmp |= (SWAPu32(HW_DMA_ICR) & ~value) & 0x7f000000;
+			if ((tmp & HW_DMA_ICR_GLOBAL_ENABLE && tmp & 0x7f000000)
+			    || tmp & HW_DMA_ICR_BUS_ERROR) {
+				if (!(SWAPu32(HW_DMA_ICR) & HW_DMA_ICR_IRQ_SENT))
+					psxHu32ref(0x1070) |= SWAP32(8);
+				tmp |= HW_DMA_ICR_IRQ_SENT;
+			}
+			HW_DMA_ICR = SWAPu32(tmp);
 			return;
 		}
 
diff --git a/libpcsxcore/psxhw.h b/libpcsxcore/psxhw.h
index cd4e928c..1d1822f8 100644
--- a/libpcsxcore/psxhw.h
+++ b/libpcsxcore/psxhw.h
@@ -57,11 +57,21 @@ extern "C" {
 #define HW_DMA_PCR   (psxHu32ref(0x10f0))
 #define HW_DMA_ICR   (psxHu32ref(0x10f4))
 
-#define	DMA_INTERRUPT(n) \
-	if (SWAPu32(HW_DMA_ICR) & (1 << (16 + n))) {    \
-		HW_DMA_ICR |= SWAP32(1 << (24 + n));        \
-		psxHu32ref(0x1070) |= SWAP32(8);            \
-	}
+#define HW_DMA_ICR_BUS_ERROR     (1<<15)
+#define HW_DMA_ICR_GLOBAL_ENABLE (1<<23)
+#define HW_DMA_ICR_IRQ_SENT      (1<<31)
+
+#define DMA_INTERRUPT(n) { \
+	u32 icr = SWAPu32(HW_DMA_ICR); \
+	if (icr & (1 << (16 + n))) { \
+		icr |= 1 << (24 + n); \
+		if (icr & HW_DMA_ICR_GLOBAL_ENABLE && !(icr & HW_DMA_ICR_IRQ_SENT)) { \
+			psxHu32ref(0x1070) |= SWAP32(8); \
+			icr |= HW_DMA_ICR_IRQ_SENT; \
+		} \
+		HW_DMA_ICR = SWAP32(icr); \
+	} \
+}
 
 void psxHwReset();
 u8 psxHwRead8(u32 add);
-- 
2.39.2