Merge pull request #3344 from kaspar030/fix_native_timer_possible_underflow

native: periph/timer: prevent underflow in timer_set_absolute
8 years ago · d15f0990b3
parent f95aaa6bf6 ec441e9aa6
commit d15f0990b3
1 changed files with 8 additions and 1 deletions
--- a/cpu/native/periph/timer.c
+++ b/cpu/native/periph/timer.c
@ -133,8 +133,15 @@ int timer_set(tim_t dev, int channel, unsigned int offset)
 int timer_set_absolute(tim_t dev, int channel, unsigned int value)
 {
    uint32_t now = timer_read(dev);
+    int64_t target = (int32_t)(value - now);

-    timer_set(dev, channel, value - now);
+    DEBUG("timer_set_absolute(): delta=%lli\n", target);
+    if (target < 0 && target > -NATIVE_TIMER_MIN_RES) {
+        DEBUG("timer_set_absolute(): preventing underflow.\n");
+        target = NATIVE_TIMER_MIN_RES;
+    }
+
+    timer_set(dev, channel, target);

    return 1;
 }