diff options
| -rw-r--r-- | core/cortex-m0/task.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/core/cortex-m0/task.c b/core/cortex-m0/task.c index b067e25f62..95b758abb8 100644 --- a/core/cortex-m0/task.c +++ b/core/cortex-m0/task.c @@ -329,6 +329,13 @@ static uint32_t __wait_evt(int timeout_us, task_id_t resched) ASSERT(ret == EC_SUCCESS); } while (!(evt = atomic_read_clear(&tsk->events))) { + /* + * We need to ensure that the execution priority is actually + * decreased after the "cpsie i" in the atomic operation above + * else the "svc" in the __schedule call below will trigger + * a HardFault. Use a barrier to force it at that point. + */ + asm volatile("isb"); /* Remove ourself and get the next task in the scheduler */ __schedule(1, resched); resched = TASK_ID_IDLE; @@ -354,10 +361,19 @@ uint32_t task_set_event(task_id_t tskid, uint32_t event, int wait) need_resched_or_profiling = 1; #endif } else { - if (wait) + if (wait) { return __wait_evt(-1, tskid); - else + } else { + /* + * We need to ensure that the execution priority is + * actually decreased after the "cpsie i" in the atomic + * operation above else the "svc" in the __schedule + * call below will trigger a HardFault. + * Use a barrier to force it at that point. + */ + asm volatile("isb"); __schedule(0, tskid); + } } return 0; |