From 2097ff232cb1af768075e1ae36f68b7979edd1dd Mon Sep 17 00:00:00 2001
From: refractionpcsx2 <refraction@gmail.com>
Date: Fri, 6 Feb 2026 22:00:06 +0000
Subject: [PATCH] IOP: Fix IRQ edges for SIO2 and CDVD and SIO2 ISTAT usage

and silence a log
---
 pcsx2/CDVD/CDVD.cpp          | 10 ++++++++--
 pcsx2/IopCounters.cpp        |  4 ++--
 pcsx2/SIO/Sio2.cpp           |  7 ++++++-
 pcsx2/ps2/Iop/IopHwWrite.cpp |  2 +-
 4 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/pcsx2/CDVD/CDVD.cpp b/pcsx2/CDVD/CDVD.cpp
index aebaba2659..405bebb0b1 100644
--- a/pcsx2/CDVD/CDVD.cpp
+++ b/pcsx2/CDVD/CDVD.cpp
@@ -102,10 +102,16 @@ static void CDVD_INT(int eCycle)
 // test (which will cause the exception to be handled).
 static void cdvdSetIrq(uint id = (1 << Irq_CommandComplete))
 {
+	if (!(cdvd.IntrStat & id))
+	{
+		iopIntcIrq(2);
+		psxSetNextBranchDelta(20);
+	}
+	else
+		DevCon.Warning("CDVD trying to double issue IRQ %x", id);
+
 	cdvd.IntrStat |= id;
 	cdvd.AbortRequested = false;
-	iopIntcIrq(2);
-	psxSetNextBranchDelta(20);
 }
 
 static int mg_BIToffset(u8* buffer)
diff --git a/pcsx2/IopCounters.cpp b/pcsx2/IopCounters.cpp
index 4ef83be2e6..2b9a580d42 100644
--- a/pcsx2/IopCounters.cpp
+++ b/pcsx2/IopCounters.cpp
@@ -782,8 +782,8 @@ void psxRcntSetNewIntrMode(int index)
 	psxCounters[index].mode.overflowFlag = false;
 	psxCounters[index].mode.intrEnable = true;
 
-	if (psxCounters[index].mode.repeatIntr != psxCounters[index].currentIrqMode.repeatInterrupt || psxCounters[index].mode.toggleIntr != psxCounters[index].currentIrqMode.toggleInterrupt)
-		DevCon.Warning("Updating psxCounter[%d] mode old repeat %d new %d old toggle %d new %d", index, psxCounters[index].mode.repeatIntr, psxCounters[index].currentIrqMode.repeatInterrupt, psxCounters[index].mode.toggleIntr, psxCounters[index].currentIrqMode.toggleInterrupt);
+	//if (psxCounters[index].mode.repeatIntr != psxCounters[index].currentIrqMode.repeatInterrupt || psxCounters[index].mode.toggleIntr != psxCounters[index].currentIrqMode.toggleInterrupt)
+	//	DevCon.Warning("Updating psxCounter[%d] mode old repeat %d new %d old toggle %d new %d", index, psxCounters[index].mode.repeatIntr, psxCounters[index].currentIrqMode.repeatInterrupt, psxCounters[index].mode.toggleIntr, psxCounters[index].currentIrqMode.toggleInterrupt);
 	
 	psxCounters[index].currentIrqMode.repeatInterrupt = psxCounters[index].mode.repeatIntr;
 	psxCounters[index].currentIrqMode.toggleInterrupt = psxCounters[index].mode.toggleIntr;
diff --git a/pcsx2/SIO/Sio2.cpp b/pcsx2/SIO/Sio2.cpp
index 93e9f74355..ed790085ed 100644
--- a/pcsx2/SIO/Sio2.cpp
+++ b/pcsx2/SIO/Sio2.cpp
@@ -100,7 +100,12 @@ void Sio2::SoftReset()
 
 void Sio2::Interrupt()
 {
-	iopIntcIrq(17);
+	if (!iStat)
+		iopIntcIrq(17);
+	else
+		DevCon.Warning("Nearly sent double SIO2 IRQ");
+
+	iStat |= 1;
 }
 
 void Sio2::SetCtrl(u32 value)
diff --git a/pcsx2/ps2/Iop/IopHwWrite.cpp b/pcsx2/ps2/Iop/IopHwWrite.cpp
index 7f1f9c7703..54387e07da 100644
--- a/pcsx2/ps2/Iop/IopHwWrite.cpp
+++ b/pcsx2/ps2/Iop/IopHwWrite.cpp
@@ -653,7 +653,7 @@ void iopHwWrite32_Page8( u32 addr, mem32_t val )
 					break;
 				case (HW_SIO2_INTR & 0x0fff):
 					Sio2Log.WriteLn("%s(%08X, %08X) SIO2 ISTAT Write", __FUNCTION__, addr, val);
-					g_Sio2.iStat = val;
+					g_Sio2.iStat &= ~val;
 					break;
 				// Other SIO2 registers are read-only, no-ops on write.
 				default: