From 6901d0e45dbf77671d86cb9bf9af98c486db97c8 Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Wed, 9 Oct 2013 02:26:52 +0300
Subject: [PATCH] fix yet another sync issue..

---
 pico/cd/mcd.c    | 35 +++++++++++++++++++++++++++++++++--
 pico/cd/memory.c |  6 ++++++
 pico/pico_int.h  | 29 +++++++++++++++--------------
 3 files changed, 54 insertions(+), 16 deletions(-)

diff --git a/pico/cd/mcd.c b/pico/cd/mcd.c
index a20b01dc..687dfc3c 100644
--- a/pico/cd/mcd.c
+++ b/pico/cd/mcd.c
@@ -90,7 +90,32 @@ PICO_INTERNAL int PicoResetMCD(void)
   return 0;
 }
 
-static __inline void SekRunS68k(unsigned int to)
+static void SekRunM68kOnce(void)
+{
+  int cyc_do;
+  pevt_log_m68k_o(EVT_RUN_START);
+
+  if ((cyc_do = SekCycleAim - SekCycleCnt) > 0) {
+    SekCycleCnt += cyc_do;
+
+#if defined(EMU_C68K)
+    PicoCpuCM68k.cycles = cyc_do;
+    CycloneRun(&PicoCpuCM68k);
+    SekCycleCnt -= PicoCpuCM68k.cycles;
+#elif defined(EMU_M68K)
+    SekCycleCnt += m68k_execute(cyc_do) - cyc_do;
+#elif defined(EMU_F68K)
+    SekCycleCnt += fm68k_emulate(cyc_do, 0) - cyc_do;
+#endif
+  }
+
+  SekCyclesLeft = 0;
+
+  SekTrace(0);
+  pevt_log_m68k_o(EVT_RUN_END);
+}
+
+static void SekRunS68k(unsigned int to)
 {
   int cyc_do;
 
@@ -305,7 +330,13 @@ void pcd_run_cpus_normal(int m68k_cycles)
     SekCycleCnt = SekCycleAim - (s68k_left * 40220 >> 16);
   }
 
-  SekSyncM68k();
+  while (CYCLES_GT(SekCycleAim, SekCycleCnt)) {
+    SekRunM68kOnce();
+    if (Pico_mcd->m.need_sync) {
+      Pico_mcd->m.need_sync = 0;
+      pcd_sync_s68k(SekCycleCnt, 0);
+    }
+  }
 }
 
 void pcd_run_cpus_lockstep(int m68k_cycles)
diff --git a/pico/cd/memory.c b/pico/cd/memory.c
index 05510788..acf29c64 100644
--- a/pico/cd/memory.c
+++ b/pico/cd/memory.c
@@ -67,6 +67,12 @@ static void remap_word_ram(u32 r3);
 void m68k_comm_check(u32 a)
 {
   pcd_sync_s68k(SekCyclesDone(), 0);
+  if (a >= 0x0e && !Pico_mcd->m.need_sync) {
+    // there are cases when slave updates comm and only switches RAM
+    // over after that (mcd1b), so there must be a resync..
+    SekEndRun(64);
+    Pico_mcd->m.need_sync = 1;
+  }
   if (SekNotPolling || a != Pico_mcd->m.m68k_poll_a) {
     Pico_mcd->m.m68k_poll_a = a;
     Pico_mcd->m.m68k_poll_cnt = 0;
diff --git a/pico/pico_int.h b/pico/pico_int.h
index 76c4812e..48d52372 100644
--- a/pico/pico_int.h
+++ b/pico/pico_int.h
@@ -396,20 +396,21 @@ struct mcd_pcm
 
 struct mcd_misc
 {
-	unsigned short hint_vector;
-	unsigned char  busreq;		// not s68k_regs[1]
-	unsigned char  s68k_pend_ints;
-	unsigned int   state_flags;	// 04
-	unsigned int   stopwatch_base_c;
-	unsigned short m68k_poll_a;
-	unsigned short m68k_poll_cnt;
-	unsigned short s68k_poll_a;
-	unsigned short s68k_poll_cnt;
-	unsigned int   s68k_poll_clk;
-	unsigned char  bcram_reg;	// 18: battery-backed RAM cart register
-	unsigned char  dmna_ret_2m;
-	unsigned short pad3;
-	int pad4[9];
+  unsigned short hint_vector;
+  unsigned char  busreq;          // not s68k_regs[1]
+  unsigned char  s68k_pend_ints;
+  unsigned int   state_flags;     // 04
+  unsigned int   stopwatch_base_c;
+  unsigned short m68k_poll_a;
+  unsigned short m68k_poll_cnt;
+  unsigned short s68k_poll_a;
+  unsigned short s68k_poll_cnt;
+  unsigned int   s68k_poll_clk;
+  unsigned char  bcram_reg;       // 18: battery-backed RAM cart register
+  unsigned char  dmna_ret_2m;
+  unsigned char  need_sync;
+  unsigned char  pad3;
+  int pad4[9];
 };
 
 typedef struct
-- 
2.39.5