From 021e47b37557361ec880c92620c7cc1292d2f2c6 Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Mon, 23 Sep 2013 20:01:37 +0300
Subject: [PATCH] cd: pcm: tune addr reload

fahrenheit..
---
 pico/cd/mcd.c   |  1 +
 pico/cd/pcm.c   | 33 ++++++++++++++++-----------------
 pico/pico_int.h |  3 ++-
 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/pico/cd/mcd.c b/pico/cd/mcd.c
index ef8d8f2..6a978f8 100644
--- a/pico/cd/mcd.c
+++ b/pico/cd/mcd.c
@@ -327,6 +327,7 @@ void pcd_state_loaded(void)
   memset(Pico_mcd->pcm_mixbuf, 0, sizeof(Pico_mcd->pcm_mixbuf));
   Pico_mcd->pcm_mixbuf_dirty = 0;
   Pico_mcd->pcm_mixpos = 0;
+  Pico_mcd->pcm_regs_dirty = 1;
 
   // old savestates..
   cycles = pcd_cycles_m68k_to_s68k(SekCycleAim);
diff --git a/pico/cd/pcm.c b/pico/cd/pcm.c
index a1276f9..77bfa30 100644
--- a/pico/cd/pcm.c
+++ b/pico/cd/pcm.c
@@ -6,7 +6,6 @@
  * See COPYING file in the top-level directory.
  */
 
-#include <assert.h>
 #include "../pico_int.h"
 
 #define PCM_STEP_SHIFT 11
@@ -30,19 +29,11 @@ void pcd_pcm_write(unsigned int a, unsigned int d)
     Pico_mcd->pcm.control = d;
     elprintf(EL_CD, "pcm control %02x", Pico_mcd->pcm.control);
   }
-  else if (a == 8 && Pico_mcd->pcm.enabled != (u_char)~d)
+  else if (a == 8)
   {
-    // sound on/off
-    int was_enabled = Pico_mcd->pcm.enabled;
-    int i;
-
-    for (i = 0; i < 8; i++)
-      if (!(was_enabled & (1 << i)))
-        Pico_mcd->pcm.ch[i].addr =
-          Pico_mcd->pcm.ch[i].regs[6] << (PCM_STEP_SHIFT + 8);
-
     Pico_mcd->pcm.enabled = ~d;
   }
+  Pico_mcd->pcm_regs_dirty = 1;
 }
 
 unsigned int pcd_pcm_read(unsigned int a)
@@ -65,29 +56,37 @@ void pcd_pcm_sync(unsigned int to)
   struct pcm_chan *ch;
   unsigned int addr;
   int c, s, steps;
+  int enabled;
   int *out;
 
   if ((int)(to - cycles) < 384)
     return;
 
   steps = (to - cycles) / 384;
+  if (Pico_mcd->pcm_mixpos + steps > PCM_MIXBUF_LEN)
+    // shouldn't happen, but occasionally does
+    steps = PCM_MIXBUF_LEN - Pico_mcd->pcm_mixpos;
 
   // PCM disabled or all channels off
-  if (!(Pico_mcd->pcm.control & 0x80) || !Pico_mcd->pcm.enabled)
+  enabled = Pico_mcd->pcm.enabled;
+  if (!(Pico_mcd->pcm.control & 0x80))
+    enabled = 0;
+  if (!enabled && !Pico_mcd->pcm_regs_dirty)
     goto end;
 
   out = Pico_mcd->pcm_mixbuf + Pico_mcd->pcm_mixpos * 2;
   Pico_mcd->pcm_mixbuf_dirty = 1;
-  if (Pico_mcd->pcm_mixpos + steps > PCM_MIXBUF_LEN)
-    // shouldn't happen
-    steps = PCM_MIXBUF_LEN - Pico_mcd->pcm_mixpos;
+  Pico_mcd->pcm_regs_dirty = 0;
 
   for (c = 0; c < 8; c++)
   {
-    if (!(Pico_mcd->pcm.enabled & (1 << c)))
+    ch = &Pico_mcd->pcm.ch[c];
+
+    if (!(enabled & (1 << c))) {
+      ch->addr = ch->regs[6] << (PCM_STEP_SHIFT + 8);
       continue; // channel disabled
+    }
 
-    ch = &Pico_mcd->pcm.ch[c];
     addr = ch->addr;
     inc = *(unsigned short *)&ch->regs[2];
     mul_l = ((int)ch->regs[0] * (ch->regs[1] & 0xf)) >> (5+1); 
diff --git a/pico/pico_int.h b/pico/pico_int.h
index a33051c..41dc59d 100644
--- a/pico/pico_int.h
+++ b/pico/pico_int.h
@@ -447,7 +447,8 @@ typedef struct
 	_scd scd;
 	int pcm_mixbuf[PCM_MIXBUF_LEN * 2];
 	int pcm_mixpos;
-	int pcm_mixbuf_dirty;
+	char pcm_mixbuf_dirty;
+	char pcm_regs_dirty;
 } mcd_state;
 
 // XXX: this will need to be reworked for cart+cd support.
-- 
2.39.2