dma: don't generate irqs after aborted DMA

An idea from Shalma.
Verified on real thing with DMA2.

3 files changed, 38 insertions, 24 deletions

diff --git a/libpcsxcore/cdrom.c b/libpcsxcore/cdrom.c
index 33b76fa..1569839 100644
--- a/libpcsxcore/cdrom.c
+++ b/libpcsxcore/cdrom.c
@@ -2018,8 +2018,11 @@ void psxDma3(u32 madr, u32 bcr, u32 chcr) {
 
 void cdrDmaInterrupt()
 {
-	HW_DMA3_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(3);
+	if (HW_DMA3_CHCR & SWAP32(0x01000000))
+	{
+		HW_DMA3_CHCR &= SWAP32(~0x01000000);
+		DMA_INTERRUPT(3);
+	}
 }
 
 void cdrReset() {
diff --git a/libpcsxcore/mdec.c b/libpcsxcore/mdec.c
index b25b961..6cf2886 100644
--- a/libpcsxcore/mdec.c
+++ b/libpcsxcore/mdec.c
@@ -531,8 +531,11 @@ void psxDma0(u32 adr, u32 bcr, u32 chcr) {
 
 void mdec0Interrupt()
 {
-	HW_DMA0_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(0);
+	if (HW_DMA0_CHCR & SWAP32(0x01000000))
+	{
+		HW_DMA0_CHCR &= SWAP32(~0x01000000);
+		DMA_INTERRUPT(0);
+	}
 }
 
 #define SIZE_OF_24B_BLOCK (16*16*3)
@@ -651,22 +654,21 @@ void mdec1Interrupt() {
 	 *
 	 */
 
-	/* this else if avoid to read outside memory */
-	if(mdec.rl >= mdec.rl_end) {
-		mdec.reg1 &= ~MDEC1_STP;
-		HW_DMA0_CHCR &= SWAP32(~0x01000000);
-		DMA_INTERRUPT(0);
-		mdec.reg1 &= ~MDEC1_BUSY;
-	} else if (SWAP16(*(mdec.rl)) == MDEC_END_OF_DATA) {
-		mdec.reg1 &= ~MDEC1_STP;
-		HW_DMA0_CHCR &= SWAP32(~0x01000000);
-		DMA_INTERRUPT(0);
-		mdec.reg1 &= ~MDEC1_BUSY;
+	/* MDEC_END_OF_DATA avoids read outside memory */
+	if (mdec.rl >= mdec.rl_end || SWAP16(*(mdec.rl)) == MDEC_END_OF_DATA) {
+		mdec.reg1 &= ~(MDEC1_STP|MDEC1_BUSY);
+		if (HW_DMA0_CHCR & SWAP32(0x01000000))
+		{
+			HW_DMA0_CHCR &= SWAP32(~0x01000000);
+			DMA_INTERRUPT(0);
+		}
 	}
 
-	HW_DMA1_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(1);
-	return;
+	if (HW_DMA1_CHCR & SWAP32(0x01000000))
+	{
+		HW_DMA1_CHCR &= SWAP32(~0x01000000);
+		DMA_INTERRUPT(1);
+	}
 }
 
 int mdecFreeze(gzFile f, int Mode) {
diff --git a/libpcsxcore/psxdma.c b/libpcsxcore/psxdma.c
index df79b6d..6d7981f 100644
--- a/libpcsxcore/psxdma.c
+++ b/libpcsxcore/psxdma.c
@@ -27,8 +27,11 @@
 // Dma3   in CdRom.c
 
 void spuInterrupt() {
-	HW_DMA4_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(4);
+	if (HW_DMA4_CHCR & SWAP32(0x01000000))
+	{
+		HW_DMA4_CHCR &= SWAP32(~0x01000000);
+		DMA_INTERRUPT(4);
+	}
 }
 
 void psxDma4(u32 madr, u32 bcr, u32 chcr) { // SPU
@@ -192,8 +195,11 @@ void psxDma2(u32 madr, u32 bcr, u32 chcr) { // GPU
 }
 
 void gpuInterrupt() {
-	HW_DMA2_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(2);
+	if (HW_DMA2_CHCR & SWAP32(0x01000000))
+	{
+		HW_DMA2_CHCR &= SWAP32(~0x01000000);
+		DMA_INTERRUPT(2);
+	}
 }
 
 void psxDma6(u32 madr, u32 bcr, u32 chcr) {
@@ -239,6 +245,9 @@ void psxDma6(u32 madr, u32 bcr, u32 chcr) {
 
 void gpuotcInterrupt()
 {
-	HW_DMA6_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(6);
+	if (HW_DMA6_CHCR & SWAP32(0x01000000))
+	{
+		HW_DMA6_CHCR &= SWAP32(~0x01000000);
+		DMA_INTERRUPT(6);
+	}
 }