From 711628f3a3d07cbaa7172636bcee4ebbe6e6b98c Mon Sep 17 00:00:00 2001
From: kub <derkub@gmail.com>
Date: Mon, 24 Jun 2024 21:37:37 +0200
Subject: [PATCH] core z80, revert non-working ebde43d (bus blocking DMA)

---
 pico/memory.c   | 6 ------
 pico/pico_cmn.c | 6 ------
 pico/pico_int.h | 1 -
 3 files changed, 13 deletions(-)

diff --git a/pico/memory.c b/pico/memory.c
index 17139a0d..34d0cf7b 100644
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -565,7 +565,6 @@ void NOINLINE ctl_write_z80reset(u32 d)
         pprof_end_sub(m68k);
       }
       Pico.t.z80_busdelay &= 0xff; // also resets bus request
-      Pico.video.status &= ~PVS_Z80WAIT;
       YM2612ResetChip();
       timers_reset();
     }
@@ -1373,11 +1372,6 @@ void PicoWrite16_32x(u32 a, u32 d) {}
 static void access_68k_bus(int delay) // bus delay as Q8
 {
   // TODO: if the 68K is in DMA wait, Z80 has to wait until DMA ends
-  if (Pico.video.status & (PVS_CPUWR|PVS_CPURD)) {
-    z80_subCLeft(z80_cyclesLeft); // rather rough on both condition and action
-    // TODO the next line will cause audio lag in Overdrive 2 demo?
-    //Pico.video.status |= PVS_Z80WAIT;
-  }
 
   // 68k bus access delay for z80. The fractional part needs to be accumulated
   // until an additional cycle is full. That is then added to the integer part.
diff --git a/pico/pico_cmn.c b/pico/pico_cmn.c
index cd037899..af2e598c 100644
--- a/pico/pico_cmn.c
+++ b/pico/pico_cmn.c
@@ -125,12 +125,6 @@ static void do_timing_hacks_start(struct PicoVideo *pv)
   int cycles = PicoVideoFIFOHint();
 
   SekCyclesBurn(cycles); // prolong cpu HOLD if necessary
-  if (pv->status & PVS_Z80WAIT) {
-    Pico.t.z80c_cnt += cycles_68k_to_z80(cycles);
-    if (!(pv->status & (PVS_CPUWR|PVS_CPURD)))
-      pv->status &= ~PVS_Z80WAIT;
-  }
-
   // XXX how to handle Z80 bus cycle stealing during DMA correctly?
   if ((Pico.t.z80_buscycles -= cycles) < 0)
     Pico.t.z80_buscycles = 0;
diff --git a/pico/pico_int.h b/pico/pico_int.h
index 79997d9b..c57c5f6a 100644
--- a/pico/pico_int.h
+++ b/pico/pico_int.h
@@ -300,7 +300,6 @@ extern SH2 sh2s[2];
 #define PVS_DMAFILL   (1 << 20) // DMA fill is waiting for fill data
 #define PVS_DMABG     (1 << 21) // background DMA operation is running
 #define PVS_FIFORUN   (1 << 22) // FIFO is processing
-#define PVS_Z80WAIT   (1 << 23) // Z80 blocked by VDP DMA
 
 struct PicoVideo
 {
-- 
2.39.5