EE/DMA: Try to avoid very small DMA loops

pcsx2/R5900.cpp

@@ -54,6 +54,7 @@ R5900cpu *Cpu = NULL;
 static const uint eeWaitCycles = 3072;
 
 bool eeEventTestIsActive = false;
+EE_intProcessStatus eeRunInterruptScan = INT_NOT_RUNNING;
 
 u32 g_eeloadMain = 0, g_eeloadExec = 0, g_osdsys_str = 0;
 
@@ -277,6 +278,11 @@ static __fi bool _cpuTestInterrupts()
 		//Console.Write("DMAC Disabled or suspended");
 		return false;
 	}
+
+	eeRunInterruptScan = INT_RUNNING;
+
+	while (eeRunInterruptScan == INT_RUNNING)
+	{
 		/* These are 'pcsx2 interrupts', they handle asynchronous stuff
 		   that depends on the cycle timings */
 		TESTINT(VU_MTVU_BUSY, MTVUInterrupt);
@@ -308,6 +314,14 @@ static __fi bool _cpuTestInterrupts()
 			TESTINT(VIF_VU1_FINISH, vif1VUFinish);
 		}
 
+		if (eeRunInterruptScan == INT_REQ_LOOP)
+			eeRunInterruptScan = INT_RUNNING;
+		else
+			break;
+	}
+
+	eeRunInterruptScan = INT_NOT_RUNNING;
+
 	if ((cpuRegs.interrupt & 0x1FFFF) & ~cpuRegs.dmastall)
 		return true;
 	else
@@ -391,6 +405,8 @@ __fi void _cpuEventTest_Shared()
 	// These are basically just DMAC-related events, which also piggy-back the same bits as
 	// the PS2's own DMA channel IRQs and IRQ Masks.
 
+	if (cpuRegs.interrupt)
+	{
 		// This is a BIOS hack because the coding in the BIOS is terrible but the bug is masked by Data Cache
 		// where a DMA buffer is overwritten without waiting for the transfer to end, which causes the fonts to get all messed up
 		// so to fix it, we run all the DMA's instantly when in the BIOS.
@@ -402,6 +418,7 @@ __fi void _cpuEventTest_Shared()
 		}
 		else
 			_cpuTestInterrupts();
+	}
 
 	// ---- IOP -------------
 	// * It's important to run a iopEventTest before calling ExecuteBlock. This
@@ -523,6 +540,17 @@ __fi void CPU_SET_DMASTALL(EE_EventType n, bool set)
 
 __fi void CPU_INT( EE_EventType n, s32 ecycle)
 {
+	// If it's retunning too quick, just rerun the DMA, there's no point in running the EE for < 4 cycles.
+	// This causes a huge uplift in performance for ONI FMV's.
+	if (ecycle < 4 && !(cpuRegs.dmastall & (1 << n)) && eeRunInterruptScan != INT_NOT_RUNNING)
+	{
+		eeRunInterruptScan = INT_REQ_LOOP;
+		cpuRegs.interrupt |= 1 << n;
+		cpuRegs.sCycle[n] = cpuRegs.cycle;
+		cpuRegs.eCycle[n] = 0;
+		return;
+	}
+
 	// EE events happen 8 cycles in the future instead of whatever was requested.
 	// This can be used on games with PATH3 masking issues for example, or when
 	// some FMV look bad.

pcsx2/R5900.h

@@ -333,6 +333,13 @@ extern R5900cpu *Cpu;
 extern R5900cpu intCpu;
 extern R5900cpu recCpu;
 
+enum EE_intProcessStatus
+{
+	INT_NOT_RUNNING = 0,
+	INT_RUNNING,
+	INT_REQ_LOOP
+};
+
 enum EE_EventType
 {
 	DMAC_VIF0	= 0,

pcsx2/Vif1_Dma.cpp

@@ -341,7 +341,10 @@ __fi void vif1Interrupt()
 	}
 
 	if (!vif1ch.chcr.STR)
+	{
 		Console.WriteLn("Vif1 running when CHCR == %x", vif1ch.chcr._u32);
+		return;
+	}
 
 	if (vif1.irq && vif1.vifstalled.enabled && vif1.vifstalled.value == VIF_IRQ_STALL)
 	{