[Qemu-devel] [PATCH v13 7/8] hw/ptimer: Fix counter - 1 returned by ptimer_get_count for the active timer

[Dmitry Osipenko <digetx@gmail.com>]

Due to rounding down performed by ptimer_get_count, it returns counter - 1 for
the active timer. That's incorrect because counter should decrement only after
period been expired, not before. I.e. if running timer has been loaded with
value X, then timer counter should stay with X until period expired and
decrement after. Fix this by adding 1 to the counter value for the active and
unexpired timer.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 hw/core/ptimer.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c
index 9bc70f5..c9f2604 100644
--- a/hw/core/ptimer.c
+++ b/hw/core/ptimer.c
@@ -89,10 +89,10 @@ static void ptimer_tick(void *opaque)
 
 uint64_t ptimer_get_count(ptimer_state *s)
 {
+    int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     uint64_t counter;
 
-    if (s->enabled && s->delta != 0) {
-        int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    if (s->enabled && s->delta != 0 && now != s->last_event) {
         int64_t next = s->next_event;
         bool expired = (now - next >= 0);
         bool oneshot = (s->enabled == 2);
@@ -144,7 +144,7 @@ uint64_t ptimer_get_count(ptimer_state *s)
                 if ((uint32_t)(period_frac << shift))
                     div += 1;
             }
-            counter = rem / div;
+            counter = rem / div + (expired ? 0 : 1);
 
             if (expired && counter != 0) {
                 /* Wrap around periodic counter.  */
-- 
2.8.3