--- trunk/src/devices/dev_mc146818.c	2007/10/08 16:18:31	11
+++ trunk/src/devices/dev_mc146818.c	2007/10/08 16:18:38	12
@@ -25,7 +25,7 @@
  *  SUCH DAMAGE.
  *   
  *
- *  $Id: dev_mc146818.c,v 1.69 2005/05/20 07:42:12 debug Exp $
+ *  $Id: dev_mc146818.c,v 1.72 2005/08/02 07:56:37 debug Exp $
  *  
  *  MC146818 real-time clock, used by many different machines types.
  *  (DS1687 as used in some SGI machines is similar to MC146818.)
@@ -56,7 +56,7 @@
 
 /*  #define MC146818_DEBUG  */
 
-#define	TICK_STEPS_SHIFT	14
+#define	TICK_SHIFT	14
 
 
 /*  256 on DECstation, SGI uses reg at 72*4 as the Century  */
@@ -140,8 +140,7 @@
 
 	if ((d->reg[MC_REGB * 4] & MC_REGB_PIE) &&
 	     d->interrupt_every_x_cycles > 0) {
-		d->cycles_left_until_interrupt -=
-		    (1 << TICK_STEPS_SHIFT);
+		d->cycles_left_until_interrupt -= (1 << TICK_SHIFT);
 
 		if (d->cycles_left_until_interrupt < 0 ||
 		    d->cycles_left_until_interrupt >=
@@ -366,25 +365,20 @@
 #endif
 
 	/*
-	 *  For some reason, Linux/sgimips relies on the UIP bit to go
-	 *  on and off. Without this code, booting Linux takes forever:
-	 */
-	d->reg[MC_REGA * 4] &= ~MC_REGA_UIP;
-#if 1
-	/*  TODO:  solve this more nicely  */
-	if ((random() & 0xff) == 0)
-		d->reg[MC_REGA * 4] ^= MC_REGA_UIP;
-#endif
-
-	/*
-	 *  Sprite seens to wants UF interrupt status, once every second, or
+	 *  Sprite seems to wants UF interrupt status, once every second, or
 	 *  it hangs forever during bootup.  (These do not cause interrupts,
 	 *  but it is good enough... Sprite polls this, iirc.)
+	 *
+	 *  Linux on at least sgimips and evbmips (Malta) wants the UIP bit
+	 *  in REGA to be updated once a second.
 	 */
 	timet = time(NULL);
 	tmp = gmtime(&timet);
 	d->reg[MC_REGC * 4] &= ~MC_REGC_UF;
+
 	if (tmp->tm_sec != d->previous_second) {
+		d->reg[MC_REGA * 4] &= ~MC_REGA_UIP;
+
 		d->reg[MC_REGC * 4] |= MC_REGC_UF;
 		d->reg[MC_REGC * 4] |= MC_REGC_IRQF;
 		d->previous_second = tmp->tm_sec;
@@ -393,14 +387,14 @@
 		    the PF (periodic flag) bit set, even though interrupts
 		    are not enabled?  */
 		d->reg[MC_REGC * 4] |= MC_REGC_PF;
-	}
+	} else
+		d->reg[MC_REGA * 4] |= MC_REGA_UIP;
 
 	/*  RTC data is in either BCD format or binary:  */
-	if (d->use_bcd) {
+	if (d->use_bcd)
 		d->reg[MC_REGB * 4] &= ~(1 << 2);
-	} else {
+	else
 		d->reg[MC_REGB * 4] |= (1 << 2);
-	}
 
 	/*  RTC date/time is always Valid:  */
 	d->reg[MC_REGD * 4] |= MC_REGD_VRT;
@@ -649,7 +643,6 @@
 
 	mc146818_update_time(d);
 
-	machine_add_tickfunction(machine, dev_mc146818_tick,
-	    d, TICK_STEPS_SHIFT);
+	machine_add_tickfunction(machine, dev_mc146818_tick, d, TICK_SHIFT);
 }