use atomic operations for sx127x task state

components/sx127x_driver/sx127x_driver.c

@@ -67,7 +67,7 @@ esp_err_t sx127x_init(const sx127x_config_t *config, sx127x_t **handle_ptr) {
   SX127X_CHECK(hndl != NULL, "malloc error", ESP_ERR_NO_MEM);
 
   hndl->task_handle = NULL;
-  hndl->task_state  = SX127X_TASK_STOPPED;
+  atomic_init(&hndl->task_state, SX127X_TASK_STOPPED);
   memcpy(&hndl->config, config, sizeof(sx127x_config_t));
 
   ret = gpio_set_direction(config->rst_io_num, GPIO_MODE_OUTPUT);
@@ -162,7 +162,7 @@ void IRAM_ATTR sx127x_isr(void *arg) {
 static void sx127x_do_tx(sx127x_t *hndl, sx127x_packet_t *packet) {
   esp_err_t ret;
   uint8_t   op_mode, irq_flags, config_2;
-  while (hndl->task_state == SX127X_TASK_RUNNING) {
+  while (atomic_load(&hndl->task_state) == SX127X_TASK_RUNNING) {
     _TX_CHECK(sx127x_read_register(hndl, REG_OP_MODE, &op_mode));
     uint8_t mode = op_mode & SX127X_MODE;
     if (mode != SX127X_MODE_TX && mode != SX127X_MODE_FS_TX) {
@@ -286,7 +286,7 @@ void sx127x_task(void *arg) {
   sx127x_write_register(hndl, REG_OP_MODE,
                         SX127X_LONG_RANGE | SX127X_MODE_RX_CONT);
 
-  while (hndl->task_state == SX127X_TASK_RUNNING) {
+  while (atomic_load(&hndl->task_state) == SX127X_TASK_RUNNING) {
     QueueSetMemberHandle_t queue = xQueueSelectFromSet(qSet, delay_time);
     if (queue == hndl->intr_semaphore) {
       BaseType_t didRecv = xSemaphoreTake(hndl->intr_semaphore, 0);
@@ -307,7 +307,7 @@ void sx127x_task(void *arg) {
     }
   }
   ESP_LOGI(SX127X_TAG, "sx127x_task exiting");
-  hndl->task_state = SX127X_TASK_STOPPED;
+  atomic_store(&hndl->task_state, SX127X_TASK_STOPPED);
   vTaskDelete(NULL);  // must delete own task
 }
 
@@ -322,7 +322,7 @@ esp_err_t sx127x_start(sx127x_t *hndl) {
   hndl->rx_packet_queue =
       xQueueCreate(RX_QUEUE_LEN, sizeof(sx127x_rx_packet_t));
 
-  hndl->task_state = SX127X_TASK_RUNNING;
+  atomic_store(&hndl->task_state, SX127X_TASK_RUNNING);
   BaseType_t pdRet =
       xTaskCreate(sx127x_task, "sx127x_task", TASK_STACK_SIZE, (void *)hndl,
                   TASK_PRIORITY, &hndl->task_handle);
@@ -354,14 +354,14 @@ esp_err_t sx127x_stop(sx127x_t *hndl) {
 
   SX127X_CHECK(hndl->task_handle != NULL, "task has not been started",
                ESP_ERR_INVALID_STATE);
-  hndl->task_state = SX127X_TASK_STOPPING;
+  atomic_store(&hndl->task_state, SX127X_TASK_STOPPING);
   xTaskNotifyGive(hndl->task_handle);
 
   ret = gpio_isr_handler_remove(hndl->config.irq_io_num);
   SX127X_ERROR_CHECK2(ret, gpio_isr_handler_remove);
   gpio_uninstall_isr_service();
 
-  while (hndl->task_state != SX127X_TASK_STOPPED) {
+  while (atomic_load(&hndl->task_state) != SX127X_TASK_STOPPED) {
     vTaskDelay(10);
   }
   hndl->task_handle = NULL;
@@ -371,7 +371,7 @@ esp_err_t sx127x_stop(sx127x_t *hndl) {
 
 esp_err_t sx127x_send_packet(sx127x_t *hndl, const char *data,
                              size_t data_len, TickType_t ticks_to_wait) {
-  SX127X_CHECK(hndl->task_state == SX127X_TASK_RUNNING, "task not running",
+  SX127X_CHECK(atomic_load(&hndl->task_state) == SX127X_TASK_RUNNING, "task not running",
                ESP_ERR_INVALID_STATE);
   SX127X_CHECK(data_len < SX127_MAX_PACKET_LEN, "packet len too long: %d",
                ESP_ERR_INVALID_ARG, data_len);
@@ -389,6 +389,8 @@ esp_err_t sx127x_send_packet(sx127x_t *hndl, const char *data,
 
 esp_err_t sx127x_recv_packet(sx127x_t *hndl, sx127x_rx_packet_t *packet,
                              TickType_t ticks_to_wait) {
+  SX127X_CHECK(atomic_load(&hndl->task_state) == SX127X_TASK_RUNNING, "task not running",
+               ESP_ERR_INVALID_STATE);
   SX127X_CHECK(packet != NULL, "packet must not be NULL", ESP_ERR_INVALID_ARG);
   BaseType_t pdRet =
       xQueueReceive(hndl->rx_packet_queue, packet, ticks_to_wait);

components/sx127x_driver/sx127x_internal.h

@@ -3,6 +3,7 @@
 #include <freertos/queue.h>
 #include <freertos/semphr.h>
 #include <freertos/task.h>
+#include <stdatomic.h>
 
 // TODO: these should be in Kconfig
 #define TASK_STACK_SIZE (2 * 1024)
@@ -128,7 +129,7 @@ typedef struct sx127x {
   sx127x_config_t     config;
   spi_device_handle_t device_handle;
   TaskHandle_t        task_handle;
-  sx127x_task_state_t task_state;
+  _Atomic(sx127x_task_state_t) task_state;
   // binary semaphore which is given when an interrupt is received from the
   // radio
   SemaphoreHandle_t intr_semaphore;