1 files changed, 31 insertions, 28 deletions

diff --git a/hw/timer/aspeed_timer.c b/hw/timer/aspeed_timer.c
index 2c3a4d0fe7..537f072cf8 100644
--- a/hw/timer/aspeed_timer.c
+++ b/hw/timer/aspeed_timer.c
@@ -109,37 +109,40 @@ static inline uint64_t calculate_time(struct AspeedTimer *t, uint32_t ticks)
 
 static uint64_t calculate_next(struct AspeedTimer *t)
 {
-    uint64_t next = 0;
-    uint32_t rate = calculate_rate(t);
+    uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    uint64_t next;
 
-    while (!next) {
-        /* We don't know the relationship between the values in the match
-         * registers, so sort using MAX/MIN/zero. We sort in that order as the
-         * timer counts down to zero. */
-        uint64_t seq[] = {
-            calculate_time(t, MAX(t->match[0], t->match[1])),
-            calculate_time(t, MIN(t->match[0], t->match[1])),
-            calculate_time(t, 0),
-        };
-        uint64_t reload_ns;
-        uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
-
-        if (now < seq[0]) {
-            next = seq[0];
-        } else if (now < seq[1]) {
-            next = seq[1];
-        } else if (now < seq[2]) {
-            next = seq[2];
-        } else if (t->reload) {
-            reload_ns = muldiv64(t->reload, NANOSECONDS_PER_SECOND, rate);
-            t->start = now - ((now - t->start) % reload_ns);
-        } else {
-            /* no reload value, return 0 */
-            break;
-        }
+    /*
+     * We don't know the relationship between the values in the match
+     * registers, so sort using MAX/MIN/zero. We sort in that order as
+     * the timer counts down to zero.
+     */
+
+    next = calculate_time(t, MAX(t->match[0], t->match[1]));
+    if (now < next) {
+        return next;
+    }
+
+    next = calculate_time(t, MIN(t->match[0], t->match[1]));
+    if (now < next) {
+        return next;
+    }
+
+    next = calculate_time(t, 0);
+    if (now < next) {
+        return next;
+    }
+
+    /* We've missed all deadlines, fire interrupt and try again */
+    timer_del(&t->timer);
+
+    if (timer_overflow_interrupt(t)) {
+        t->level = !t->level;
+        qemu_set_irq(t->irq, t->level);
     }
 
-    return next;
+    t->start = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    return calculate_time(t, MAX(MAX(t->match[0], t->match[1]), 0));
 }
 
 static void aspeed_timer_mod(AspeedTimer *t)