From 511c3133f1a1263ace98e6709e1691956101b1d6 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Sun, 5 Jul 2020 02:25:55 +1000
Subject: [PATCH] GPU: Let GPU catch up before handling GP1 reset commands

Fixes trashed VRAM writes in some homebrew.
---
 src/core/gpu.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/core/gpu.cpp b/src/core/gpu.cpp
index db64df683..fe593d2a6 100644
--- a/src/core/gpu.cpp
+++ b/src/core/gpu.cpp
@@ -891,6 +891,7 @@ void GPU::WriteGP1(u32 value)
     case 0x00: // Reset GPU
     {
       Log_DebugPrintf("GP1 reset GPU");
+      m_command_tick_event->InvokeEarly();
       SynchronizeCRTC();
       SoftReset();
     }
@@ -899,6 +900,7 @@ void GPU::WriteGP1(u32 value)
     case 0x01: // Clear FIFO
     {
       Log_DebugPrintf("GP1 clear FIFO");
+      m_command_tick_event->InvokeEarly();
       SynchronizeCRTC();
       m_blitter_state = BlitterState::Idle;
       m_command_total_words = 0;
@@ -1007,6 +1009,7 @@ void GPU::WriteGP1(u32 value)
       {
         // Have to be careful when setting this because Synchronize() can modify GPUSTAT.
         static constexpr u32 SET_MASK = UINT32_C(0b00000000011111110100000000000000);
+        m_command_tick_event->InvokeEarly();
         SynchronizeCRTC();
         m_GPUSTAT.bits = (m_GPUSTAT.bits & ~SET_MASK) | (new_GPUSTAT.bits & SET_MASK);
         UpdateCRTCConfig();