Currently, periodic timer that has load = delta = 0 performs trigger
on timer reload and stops, printing a "period zero" error message.
Introduce new policy that makes periodic timer to continuously trigger
with a period interval in case of load = 0.
Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
hw/core/ptimer.c | 16 +++++++++++++++-
include/hw/ptimer.h | 3 +++
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c
index c697c08..8578861 100644
--- a/hw/core/ptimer.c
+++ b/hw/core/ptimer.c
@@ -44,7 +44,8 @@ static void ptimer_reload(ptimer_state *s, int delta_adjust)
ptimer_trigger(s);
delta = s->delta = s->limit;
}
- if (delta == 0 || s->period == 0) {
+
+ if (s->period == 0) {
fprintf(stderr, "Timer with period zero, disabling\n");
timer_del(s->timer);
s->enabled = 0;
@@ -55,6 +56,19 @@ static void ptimer_reload(ptimer_state *s, int delta_adjust)
delta += delta_adjust;
}
+ if (delta == 0 && (s->policy_mask & PTIMER_POLICY_CONTINUOUS_TRIGGER)) {
+ if (s->enabled == 1) {
+ delta = 1;
+ }
+ }
+
+ if (delta == 0) {
+ fprintf(stderr, "Timer with delta zero, disabling\n");
+ timer_del(s->timer);
+ s->enabled = 0;
+ return;
+ }
+
/*
* Artificially limit timeout rate to something
* achievable under QEMU. Otherwise, QEMU spends all
diff --git a/include/hw/ptimer.h b/include/hw/ptimer.h
index e8de48d..c97f02e 100644
--- a/include/hw/ptimer.h
+++ b/include/hw/ptimer.h
@@ -16,6 +16,9 @@
/* Periodic timer counter stays with "0" for a one period before wrapping
* around. */
#define PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD (1 << 0)
+/* Periodic timer that has load = 0 would continuously re-trigger every
+ * period. */
+#define PTIMER_POLICY_CONTINUOUS_TRIGGER (1 << 1)
/* ptimer.c */
typedef struct ptimer_state ptimer_state;
--
2.9.2
