Currently ptimer would print error message and clear enable flag for an
arming timer that has delta = load = 0. That actually could be a valid case
for some hardware, like instant IRQ trigger for oneshot timer or continuous
in periodic mode. Support those cases by printing error message only when
period = 0.
In addition, don't load one-shot timer when delta = 0 and actually stop the
timer by timer_del().
Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
hw/core/ptimer.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c
index 6960738..42e44f9 100644
--- a/hw/core/ptimer.c
+++ b/hw/core/ptimer.c
@@ -36,13 +36,20 @@ static void ptimer_reload(ptimer_state *s)
{
uint32_t period_frac = s->period_frac;
uint64_t period = s->period;
+ int periodic = (s->enabled == 1);
- if (s->delta == 0) {
+ if (s->delta == 0 && period != 0) {
ptimer_trigger(s);
- s->delta = s->limit;
+ if (periodic) {
+ s->delta = s->limit;
+ }
}
- if (s->delta == 0 || s->period == 0) {
- fprintf(stderr, "Timer with period zero, disabling\n");
+ if (s->delta == 0 || period == 0) {
+ if (period == 0) {
+ fprintf(stderr, "Timer with period zero, disabling\n");
+ s->delta = 0;
+ }
+ timer_del(s->timer);
s->enabled = 0;
return;
}
@@ -56,7 +63,7 @@ static void ptimer_reload(ptimer_state *s)
* on the current generation of host machines.
*/
- if ((s->enabled == 1) && !use_icount && (s->delta * period < 10000)) {
+ if (periodic && !use_icount && (s->delta * period < 10000)) {
period = 10000 / s->delta;
period_frac = 0;
}
@@ -86,14 +93,14 @@ uint64_t ptimer_get_count(ptimer_state *s)
int enabled = s->enabled;
uint64_t counter;
- if (enabled) {
+ if (enabled && s->delta != 0) {
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
int64_t next = s->next_event;
int expired = (now - next >= 0);
int oneshot = (enabled == 2);
/* Figure out the current counter value. */
- if (s->period == 0 || (expired && (use_icount || oneshot))) {
+ if (expired && (use_icount || oneshot)) {
/* Prevent timer underflowing if it should already have
triggered. */
counter = 0;
--
2.6.4
