Fix timer code for ARM systems: make sure that udelay() does not

reset timers so it's save to use udelay() in timeout code.

1 files changed, 18 insertions, 9 deletions

diff --git a/cpu/sa1100/interrupts.c b/cpu/sa1100/interrupts.c
index 93a78d707e..b393e0d435 100644
--- a/cpu/sa1100/interrupts.c
+++ b/cpu/sa1100/interrupts.c
@@ -206,15 +206,24 @@ ulong get_timer_masked (void)
 void udelay_masked (unsigned long usec)
 {
 	ulong tmo;
-
-	tmo = usec / 1000;
-	tmo *= CFG_HZ;
-	tmo /= 1000;
-
-	reset_timer_masked ();
-
-	while (tmo >= get_timer_masked ())
-		/*NOP*/;
+	ulong endtime;
+	signed long diff;
+
+	if (usec >= 1000) {
+		tmo = usec / 1000;
+		tmo *= CFG_HZ;
+		tmo /= 1000;
+	} else {
+		tmo = usec * CFG_HZ;
+		tmo /= (1000*1000);
+	}
+
+	endtime = get_timer_masked () + tmo;
+
+	do {
+		ulong now = get_timer_masked ();
+		diff = endtime - now;
+	} while (diff >= 0);
 }
 
 /*