From a085cd431dbaed77349d1e1e2f41be1b94b84535 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Lam?= <leo@innovatetechnologi.es>
Date: Wed, 8 Feb 2017 16:22:27 +0100
Subject: [PATCH] Adjust event times after a PPC clock change

This likely doesn't change much, but it makes events trigger at the
correct time after a clock change.
---
 Source/Core/Core/CoreTiming.cpp      | 10 ++++++++++
 Source/Core/Core/CoreTiming.h        |  2 ++
 Source/Core/Core/HW/SystemTimers.cpp |  2 ++
 3 files changed, 14 insertions(+)

diff --git a/Source/Core/Core/CoreTiming.cpp b/Source/Core/Core/CoreTiming.cpp
index 803cd76fec..0780d93ca4 100644
--- a/Source/Core/Core/CoreTiming.cpp
+++ b/Source/Core/Core/CoreTiming.cpp
@@ -364,6 +364,16 @@ void LogPendingEvents()
   }
 }
 
+// Should only be called from the CPU thread after the PPC clock has changed
+void AdjustEventQueueTimes(u32 new_ppc_clock, u32 old_ppc_clock)
+{
+  for (Event& ev : s_event_queue)
+  {
+    const s64 ticks = (ev.time - g_global_timer) * new_ppc_clock / old_ppc_clock;
+    ev.time = g_global_timer + ticks;
+  }
+}
+
 void Idle()
 {
   if (SConfig::GetInstance().bSyncGPUOnSkipIdleHack)
diff --git a/Source/Core/Core/CoreTiming.h b/Source/Core/Core/CoreTiming.h
index 28263be94c..2cdee0c6cf 100644
--- a/Source/Core/Core/CoreTiming.h
+++ b/Source/Core/Core/CoreTiming.h
@@ -91,6 +91,8 @@ void LogPendingEvents();
 
 std::string GetScheduledEventsSummary();
 
+void AdjustEventQueueTimes(u32 new_ppc_clock, u32 old_ppc_clock);
+
 u32 GetFakeDecStartValue();
 void SetFakeDecStartValue(u32 val);
 u64 GetFakeDecStartTicks();
diff --git a/Source/Core/Core/HW/SystemTimers.cpp b/Source/Core/Core/HW/SystemTimers.cpp
index eb72f6de47..4b3a9fda8a 100644
--- a/Source/Core/Core/HW/SystemTimers.cpp
+++ b/Source/Core/Core/HW/SystemTimers.cpp
@@ -228,10 +228,12 @@ void PreInit()
 
 void ChangePPCClock(Mode mode)
 {
+  const u32 previous_clock = s_cpu_core_clock;
   if (mode == Mode::Wii)
     s_cpu_core_clock = 729000000u;
   else
     s_cpu_core_clock = 486000000u;
+  CoreTiming::AdjustEventQueueTimes(s_cpu_core_clock, previous_clock);
 }
 
 void Init()