--- process.c.origional	2004-04-06 19:14:01.000000000 +1000
+++ process.c	2004-04-06 19:13:44.000000000 +1000
@@ -50,6 +50,7 @@
 #include <asm/math_emu.h>
 #endif
 
+#include <asm/apic.h>
 #include <linux/irq.h>
 #include <linux/err.h>
 
@@ -88,7 +89,7 @@ EXPORT_SYMBOL(enable_hlt);
  * We use this if we don't have any better
  * idle routine..
  */
-void default_idle(void)
+static void default_idle(void)
 {
 	if (!hlt_counter && current_cpu_data.hlt_works_ok) {
 		local_irq_disable();
@@ -99,6 +100,28 @@ void default_idle(void)
 	}
 }
 
+ /*
+ * We use this to avoid nforce2 lockups
+ * Reduces frequency of C1 disconnects
+ */
+static void c1halt_idle(void)
+{
+	if (!hlt_counter && current_cpu_data.hlt_works_ok) {
+		local_irq_disable();
+		/* only hlt disconnect if more than 1.6% of apic interval remains */
+		if( (!need_resched()) &&
+			(apic_read(APIC_TMCCT) > (apic_read(APIC_TMICT)>>6))) {
+			ndelay(600); /* helps nforce2 but adds 0.6us hard int latency */
+			safe_halt();  /* nothing better to do until we wake up */
+		}
+		else
+			local_irq_enable();
+	}
+}
+
+
+
+
 /*
  * On SMP it's slightly faster (but much more power-consuming!)
  * to poll the ->work.need_resched flag instead of waiting for the
@@ -137,16 +160,14 @@ static void poll_idle (void)
  * low exit latency (ie sit in a loop waiting for
  * somebody to say that they'd like to reschedule)
  */
+static void (*idle)(void);
 void cpu_idle (void)
 {
 	/* endless idle loop with no priority at all */
 	while (1) {
 		while (!need_resched()) {
-			void (*idle)(void) = pm_idle;
-
 			if (!idle)
-				idle = default_idle;
-
+				idle = pm_idle ? pm_idle : default_idle;
 			irq_stat[smp_processor_id()].idle_timestamp = jiffies;
 			idle();
 		}
@@ -201,10 +222,13 @@ static int __init idle_setup (char *str)
 {
 	if (!strncmp(str, "poll", 4)) {
 		printk("using polling idle threads.\n");
-		pm_idle = poll_idle;
+		idle = poll_idle;
 	} else if (!strncmp(str, "halt", 4)) {
 		printk("using halt in idle threads.\n");
-		pm_idle = default_idle;
+	  idle = default_idle;
+	} else if (!strncmp(str, "C1halt", 6)) {
+		printk("using C1 halt disconnect friendly idle threads.\n");
+		idle = c1halt_idle;
 	}
 
 	return 1;