[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>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/arm/mach-ns9xxx/irq.c b/arch/arm/mach-ns9xxx/irq.c
index cd8f8365b62e..b8c7b00522e6 100644
--- a/arch/arm/mach-ns9xxx/irq.c
+++ b/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;