gptimer: fix race condition between start and stop

Added state transition in gptimer_start/stop functions.
So that it's not possible to make a stopped timer continue to run
because of race condition.
This commit is contained in:
morris
2023-03-06 13:32:35 +08:00
parent ed97d230c8
commit 2d52334e5d
11 changed files with 153 additions and 74 deletions

View File

@@ -136,7 +136,8 @@ esp_err_t gptimer_new_timer(const gptimer_config_t *config, gptimer_handle_t *re
portEXIT_CRITICAL(&group->spinlock);
// initialize other members of timer
timer->spinlock = (portMUX_TYPE)portMUX_INITIALIZER_UNLOCKED;
timer->fsm = GPTIMER_FSM_INIT; // put the timer into init state
// put the timer driver to the init state
atomic_init(&timer->fsm, GPTIMER_FSM_INIT);
timer->direction = config->direction;
timer->flags.intr_shared = config->flags.intr_shared;
ESP_LOGD(TAG, "new gptimer (%d,%d) at %p, resolution=%"PRIu32"Hz", group_id, timer_id, timer, timer->resolution_hz);
@@ -153,7 +154,7 @@ err:
esp_err_t gptimer_del_timer(gptimer_handle_t timer)
{
ESP_RETURN_ON_FALSE(timer, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
ESP_RETURN_ON_FALSE(timer->fsm == GPTIMER_FSM_INIT, ESP_ERR_INVALID_STATE, TAG, "timer not in init state");
ESP_RETURN_ON_FALSE(atomic_load(&timer->fsm) == GPTIMER_FSM_INIT, ESP_ERR_INVALID_STATE, TAG, "timer not in init state");
gptimer_group_t *group = timer->group;
gptimer_clock_source_t clk_src = timer->clk_src;
int group_id = group->group_id;
@@ -231,7 +232,7 @@ esp_err_t gptimer_register_event_callbacks(gptimer_handle_t timer, const gptimer
// lazy install interrupt service
if (!timer->intr) {
ESP_RETURN_ON_FALSE(timer->fsm == GPTIMER_FSM_INIT, ESP_ERR_INVALID_STATE, TAG, "timer not in init state");
ESP_RETURN_ON_FALSE(atomic_load(&timer->fsm) == GPTIMER_FSM_INIT, ESP_ERR_INVALID_STATE, TAG, "timer not in init state");
// if user wants to control the interrupt allocation more precisely, we can expose more flags in `gptimer_config_t`
int isr_flags = timer->flags.intr_shared ? ESP_INTR_FLAG_SHARED | GPTIMER_INTR_ALLOC_FLAGS : GPTIMER_INTR_ALLOC_FLAGS;
ESP_RETURN_ON_ERROR(esp_intr_alloc_intrstatus(timer_group_periph_signals.groups[group_id].timer_irq_id[timer_id], isr_flags,
@@ -283,63 +284,79 @@ esp_err_t gptimer_set_alarm_action(gptimer_handle_t timer, const gptimer_alarm_c
esp_err_t gptimer_enable(gptimer_handle_t timer)
{
ESP_RETURN_ON_FALSE(timer, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
ESP_RETURN_ON_FALSE(timer->fsm == GPTIMER_FSM_INIT, ESP_ERR_INVALID_STATE, TAG, "timer not in init state");
gptimer_fsm_t expected_fsm = GPTIMER_FSM_INIT;
ESP_RETURN_ON_FALSE(atomic_compare_exchange_strong(&timer->fsm, &expected_fsm, GPTIMER_FSM_ENABLE),
ESP_ERR_INVALID_STATE, TAG, "timer not in init state");
// acquire power manager lock
if (timer->pm_lock) {
ESP_RETURN_ON_ERROR(esp_pm_lock_acquire(timer->pm_lock), TAG, "acquire pm_lock failed");
}
// enable interrupt service
if (timer->intr) {
ESP_RETURN_ON_ERROR(esp_intr_enable(timer->intr), TAG, "enable interrupt service failed");
}
timer->fsm = GPTIMER_FSM_ENABLE;
return ESP_OK;
}
esp_err_t gptimer_disable(gptimer_handle_t timer)
{
ESP_RETURN_ON_FALSE(timer, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
ESP_RETURN_ON_FALSE(timer->fsm == GPTIMER_FSM_ENABLE, ESP_ERR_INVALID_STATE, TAG, "timer not in enable state");
gptimer_fsm_t expected_fsm = GPTIMER_FSM_ENABLE;
ESP_RETURN_ON_FALSE(atomic_compare_exchange_strong(&timer->fsm, &expected_fsm, GPTIMER_FSM_INIT),
ESP_ERR_INVALID_STATE, TAG, "timer not in enable state");
// disable interrupt service
if (timer->intr) {
ESP_RETURN_ON_ERROR(esp_intr_disable(timer->intr), TAG, "disable interrupt service failed");
}
// release power manager lock
if (timer->pm_lock) {
ESP_RETURN_ON_ERROR(esp_pm_lock_release(timer->pm_lock), TAG, "release pm_lock failed");
}
timer->fsm = GPTIMER_FSM_INIT;
return ESP_OK;
}
esp_err_t gptimer_start(gptimer_handle_t timer)
{
ESP_RETURN_ON_FALSE_ISR(timer, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
ESP_RETURN_ON_FALSE_ISR(timer->fsm == GPTIMER_FSM_ENABLE, ESP_ERR_INVALID_STATE, TAG, "timer not enabled yet");
portENTER_CRITICAL_SAFE(&timer->spinlock);
timer_ll_enable_counter(timer->hal.dev, timer->timer_id, true);
timer_ll_enable_alarm(timer->hal.dev, timer->timer_id, timer->flags.alarm_en);
portEXIT_CRITICAL_SAFE(&timer->spinlock);
gptimer_fsm_t expected_fsm = GPTIMER_FSM_ENABLE;
if (atomic_compare_exchange_strong(&timer->fsm, &expected_fsm, GPTIMER_FSM_RUN_WAIT)) {
// the register used by the following LL functions are shared with other API,
// which is possible to run along with this function, so we need to protect
portENTER_CRITICAL_SAFE(&timer->spinlock);
timer_ll_enable_counter(timer->hal.dev, timer->timer_id, true);
timer_ll_enable_alarm(timer->hal.dev, timer->timer_id, timer->flags.alarm_en);
portEXIT_CRITICAL_SAFE(&timer->spinlock);
} else {
ESP_RETURN_ON_FALSE_ISR(false, ESP_ERR_INVALID_STATE, TAG, "timer is not enabled yet");
}
atomic_store(&timer->fsm, GPTIMER_FSM_RUN);
return ESP_OK;
}
esp_err_t gptimer_stop(gptimer_handle_t timer)
{
ESP_RETURN_ON_FALSE_ISR(timer, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
ESP_RETURN_ON_FALSE_ISR(timer->fsm == GPTIMER_FSM_ENABLE, ESP_ERR_INVALID_STATE, TAG, "timer not enabled yet");
// disable counter, alarm, auto-reload
portENTER_CRITICAL_SAFE(&timer->spinlock);
timer_ll_enable_counter(timer->hal.dev, timer->timer_id, false);
timer_ll_enable_alarm(timer->hal.dev, timer->timer_id, false);
portEXIT_CRITICAL_SAFE(&timer->spinlock);
gptimer_fsm_t expected_fsm = GPTIMER_FSM_RUN;
if (atomic_compare_exchange_strong(&timer->fsm, &expected_fsm, GPTIMER_FSM_ENABLE_WAIT)) {
// disable counter, alarm, auto-reload
portENTER_CRITICAL_SAFE(&timer->spinlock);
timer_ll_enable_counter(timer->hal.dev, timer->timer_id, false);
timer_ll_enable_alarm(timer->hal.dev, timer->timer_id, false);
portEXIT_CRITICAL_SAFE(&timer->spinlock);
} else {
ESP_RETURN_ON_FALSE_ISR(false, ESP_ERR_INVALID_STATE, TAG, "timer is not running");
}
atomic_store(&timer->fsm, GPTIMER_FSM_ENABLE);
return ESP_OK;
}
@@ -498,21 +515,3 @@ IRAM_ATTR static void gptimer_default_isr(void *args)
portYIELD_FROM_ISR();
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///// The Following APIs are for internal use only (e.g. unit test) /////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
esp_err_t gptimer_get_intr_handle(gptimer_handle_t timer, intr_handle_t *ret_intr_handle)
{
ESP_RETURN_ON_FALSE(timer && ret_intr_handle, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
*ret_intr_handle = timer->intr;
return ESP_OK;
}
esp_err_t gptimer_get_pm_lock(gptimer_handle_t timer, esp_pm_lock_handle_t *ret_pm_lock)
{
ESP_RETURN_ON_FALSE(timer && ret_pm_lock, ESP_ERR_INVALID_ARG, TAG, "invalid argument");
*ret_pm_lock = timer->pm_lock;
return ESP_OK;
}