[ARM] 4493/1: ns9xxx: disable a non-reloading timer before ack'ing its irq

The HRM states that is must be done this way ...

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-ns9xxx/irq.c

@@ -21,6 +21,15 @@ static void ns9xxx_ack_irq_timer(unsigned int irq)
 {
 	u32 tc = SYS_TC(irq - IRQ_TIMER0);
 
+	/*
+	 * If the timer is programmed to halt on terminal count, the
+	 * timer must be disabled before clearing the interrupt.
+	 */
+	if (REGGET(tc, SYS_TCx, REN) == 0) {
+		REGSET(tc, SYS_TCx, TEN, DIS);
+		SYS_TC(irq - IRQ_TIMER0) = tc;
+	}
+
 	REGSET(tc, SYS_TCx, INTC, SET);
 	SYS_TC(irq - IRQ_TIMER0) = tc;