[Qemu-devel] [PATCH 1/3 v3] arm_mptimer: Fix timer shutdown

[Dmitry Osipenko <digetx@gmail.com>]

Timer, running in periodic mode, can't be stopped or coming one-shot tick
won't be canceled because timer control code just doesn't handle timer
disabling. Fix it by deleting timer if enable bit isn't set.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---

v2: Avoid calling timer_del() if the timer was already disabled as per
    Peter Maydell suggestion.

v3: Do not change "reload the timer" logic as it is separate bug.

 hw/timer/arm_mptimer.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/timer/arm_mptimer.c b/hw/timer/arm_mptimer.c
index 8b93b3c..e230063 100644
--- a/hw/timer/arm_mptimer.c
+++ b/hw/timer/arm_mptimer.c
@@ -122,11 +122,17 @@ static void timerblock_write(void *opaque, hwaddr addr,
     case 8: /* Control.  */
         old = tb->control;
         tb->control = value;
-        if (((old & 1) == 0) && (value & 1)) {
+        if ((old & 1) == (value & 1)) {
+            break;
+        }
+        if (value & 1) {
             if (tb->count == 0 && (tb->control & 2)) {
                 tb->count = tb->load;
             }
             timerblock_reload(tb, 1);
+        } else {
+            /* Shutdown timer.  */
+            timer_del(tb->timer);
         }
         break;
     case 12: /* Interrupt status.  */
-- 
2.4.4