psxbios: Improve WaitEvent behaviour according to documentation

[pcsx_rearmed.git] / libpcsxcore / psxbios.c

diff --git a/libpcsxcore/psxbios.c b/libpcsxcore/psxbios.c
index fc28ff8..139c8a5 100644 (file)
--- a/libpcsxcore/psxbios.c
+++ b/libpcsxcore/psxbios.c
@@ -1562,14 +1562,28 @@ void psxBios_WaitEvent() { // 0a
 
        ev   = a0 & 0xff;
        spec = (a0 >> 8) & 0xff;
-
 #ifdef PSXBIOS_LOG
        PSXBIOS_LOG("psxBios_%s %x,%x\n", biosB0n[0x0a], ev, spec);
 #endif
+       if (Event[ev][spec].status == EvStUNUSED)
+       {
+               v0 = 0;
+               pc0 = ra;       
+               return;
+       }
 
-       Event[ev][spec].status = EvStACTIVE;
+       if (Event[ev][spec].status == EvStALREADY) 
+       {
+               /* Callback events (mode=EvMdINTR) do never set the ready flag (and thus WaitEvent would hang forever). */
+               if (!(Event[ev][spec].mode == EvMdINTR)) Event[ev][spec].status = EvStACTIVE;
+               v0 = 1;
+               pc0 = ra;
+               return;
+       }
 
-       v0 = 1; pc0 = ra;
+       v0 = 0;
+       pc0 = ra;
+       ResetIoCycle();
 }
 
 void psxBios_TestEvent() { // 0b