add a nasty hack for gpu busy timing

[pcsx_rearmed.git] / libpcsxcore / psxhw.c

diff --git a/libpcsxcore/psxhw.c b/libpcsxcore/psxhw.c
index 60ff6c4..254693e 100644 (file)
--- a/libpcsxcore/psxhw.c
+++ b/libpcsxcore/psxhw.c
@@ -32,6 +32,8 @@
 #define PAD_LOG(...)
 #endif
 
+static u32 (*psxHwReadGpuSRptr)(void) = psxHwReadGpuSR;
+
 void psxHwReset() {
        memset(psxH, 0, 0x10000);
 
@@ -39,6 +41,8 @@ void psxHwReset() {
        cdrReset();
        psxRcntInit();
        HW_GPU_STATUS = SWAP32(0x14802000);
+       psxHwReadGpuSRptr = Config.hacks.gpu_busy_hack
+               ? psxHwReadGpuSRbusyHack : psxHwReadGpuSR;
 }
 
 void psxHwWriteIstat(u32 value)
@@ -78,6 +82,39 @@ void psxHwWriteDmaIcr32(u32 value)
        HW_DMA_ICR = SWAPu32(tmp);
 }
 
+void psxHwWriteGpuSR(u32 value)
+{
+       GPU_writeStatus(value);
+       gpuSyncPluginSR();
+}
+
+u32 psxHwReadGpuSR(void)
+{
+       u32 v;
+
+       // meh2, syncing for img bit, might want to avoid it..
+       gpuSyncPluginSR();
+       v = HW_GPU_STATUS;
+
+       // XXX: because of large timeslices can't use hSyncCount, using rough
+       // approximization instead. Perhaps better use hcounter code here or something.
+       if (hSyncCount < 240 && (HW_GPU_STATUS & PSXGPU_ILACE_BITS) != PSXGPU_ILACE_BITS)
+               v |= PSXGPU_LCF & (psxRegs.cycle << 20);
+       return v;
+}
+
+// a hack due to poor timing of gpu idle bit
+// to get rid of this, GPU draw times, DMAs, cpu timing has to fall within
+// certain timing window or else games like "ToHeart" softlock
+u32 psxHwReadGpuSRbusyHack(void)
+{
+       u32 v = psxHwReadGpuSR();
+       static u32 hack;
+       if (!(hack++ & 3))
+               v &= ~PSXGPU_nBUSY;
+       return v;
+}
+
 u8 psxHwRead8(u32 add) {
        unsigned char hard;
 
@@ -302,10 +339,7 @@ u32 psxHwRead32(u32 add) {
 #endif
                        return hard;
                case 0x1f801814:
-                       gpuSyncPluginSR();
-                       hard = SWAP32(HW_GPU_STATUS);
-                       if (hSyncCount < 240 && (hard & PSXGPU_ILACE_BITS) != PSXGPU_ILACE_BITS)
-                               hard |= PSXGPU_LCF & (psxRegs.cycle << 20);
+                       hard = psxHwReadGpuSRptr();
 #ifdef PSXHW_LOG
                        PSXHW_LOG("GPU STATUS 32bit read %x\n", hard);
 #endif
@@ -771,8 +805,7 @@ void psxHwWrite32(u32 add, u32 value) {
 #ifdef PSXHW_LOG
                        PSXHW_LOG("GPU STATUS 32bit write %x\n", value);
 #endif
-                       GPU_writeStatus(value);
-                       gpuSyncPluginSR();
+                       psxHwWriteGpuSR(value);
                        return;
 
                case 0x1f801820: