Fix timer code for ARM systems: make sure that udelay() does not
reset timers so it's save to use udelay() in timeout code.
diff --git a/cpu/pxa/interrupts.c b/cpu/pxa/interrupts.c
index b335a82..0479a10 100644
--- a/cpu/pxa/interrupts.c
+++ b/cpu/pxa/interrupts.c
@@ -190,6 +190,8 @@
 void udelay_masked (unsigned long usec)
 {
 	ulong tmo;
+	ulong endtime;
+	signed long diff;
 
 	if (usec >= 1000) {
 		tmo = usec / 1000;
@@ -200,10 +202,12 @@
 		tmo /= (1000*1000);
 	}
 
-	reset_timer_masked ();
+	endtime = get_timer_masked () + tmo;
 
-	while (tmo >= get_timer_masked ())
-		/*NOP*/;
+	do {
+		ulong now = get_timer_masked ();
+		diff = endtime - now;
+	} while (diff >= 0);
 }
 
 /*