From 93eff7fac6c91bbf5f2458fe1ee09979f0d86ac3 Mon Sep 17 00:00:00 2001
From: Flyinghead <raphael.jean@gmail.com>
Date: Sun, 29 Aug 2021 11:55:42 +0200
Subject: [PATCH] sh4: fix TMU regression

introduced by 05d51cc35c57b9762e7bf12cad532a6003a2f556
fixes SA2 running too fast
---
 core/hw/sh4/modules/tmu.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/core/hw/sh4/modules/tmu.cpp b/core/hw/sh4/modules/tmu.cpp
index fde9c9816..6e07b4c8a 100644
--- a/core/hw/sh4/modules/tmu.cpp
+++ b/core/hw/sh4/modules/tmu.cpp
@@ -233,7 +233,8 @@ static int sched_tmu_cb(int ch, int sch_cycl, int jitter)
 
 			//schedule next trigger by writing the TCNT register
 			u32 tcor = TMU_TCOR(ch);
-			write_TMU_TCNTch(ch, std::max((s32)(tcor + tcnt), 0));
+			// Don't miss an underflow if tcor is less than -tcnt
+			write_TMU_TCNTch(ch, (u32)std::max<s64>((u64)tcor + (s32)tcnt, 0));
 		}
 		else {