[Qemu-devel] [PATCH v3 2/2] arm_mptimer: Respect IT bit state

[Dmitry Osipenko <digetx@gmail.com>]

The timer should fire interrupt only if IT(interrupt enable) bit state of
control register is enabled and the timer should update IRQ status on IT
bit change as it would mask/unmask the interrupt line.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---

v2: Added missed IRQ status update on control register write as per
    Peter Crosthwaite comment.

v3: No code change, just re-send.

 hw/timer/arm_mptimer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/timer/arm_mptimer.c b/hw/timer/arm_mptimer.c
index 0e132b1..22fa46e 100644
--- a/hw/timer/arm_mptimer.c
+++ b/hw/timer/arm_mptimer.c
@@ -38,7 +38,7 @@ static inline int get_current_cpu(ARMMPTimerState *s)
 
 static inline void timerblock_update_irq(TimerBlock *tb)
 {
-    qemu_set_irq(tb->irq, tb->status);
+    qemu_set_irq(tb->irq, tb->status && (tb->control & 4));
 }
 
 /* Return conversion factor from mpcore timer ticks to qemu timer ticks.  */
@@ -122,6 +122,9 @@ static void timerblock_write(void *opaque, hwaddr addr,
     case 8: /* Control.  */
         old = tb->control;
         tb->control = value;
+        if ((old & 4) != (value & 4)) {
+            timerblock_update_irq(tb);
+        }
         if (value & 1) {
             if ((old & 1) && (tb->count != 0)) {
                 /* Do nothing if timer is ticking right now.  */
-- 
2.4.4