fix stack smashing issue

components/sx127x_driver/sx127x_driver.c

@@ -146,7 +146,7 @@ esp_err_t sx127x_free(sx127x_t *handle) {
 
 void IRAM_ATTR sx127x_isr(void *arg) {
   sx127x_t *handle = (sx127x_t *)arg;
-  ESP_LOGV(SX127X_TAG, "sx127x_isr");
+  ESP_LOGI(SX127X_TAG, "sx127x_isr");
   BaseType_t hpTaskWoken;
   xSemaphoreGiveFromISR(handle->intr_semaphore, &hpTaskWoken);
   if (hpTaskWoken) {

components/sx127x_driver/sx127x_registers.c

@@ -204,14 +204,16 @@ esp_err_t sx127x_set_crc(sx127x_t *handle, sx127x_crc_t crc) {
   return ESP_OK;
 }
 
-esp_err_t sx127x_write_fifo(sx127x_t *handle, char *data, size_t data_len) {
+esp_err_t sx127x_write_fifo(sx127x_t *handle, const char *data,
+                            size_t data_len) {
   spi_transaction_t trans;
   memset(&trans, 0, sizeof(trans));
-  trans.flags     = SPI_TRANS_USE_RXDATA;
+  trans.flags     = 0;
   trans.addr      = REG_FIFO;
   trans.length    = 8 * data_len;
-  trans.rxlength  = 0;
   trans.tx_buffer = data;
+  trans.rxlength  = 0;
+  trans.rx_buffer = NULL;
 
   esp_err_t ret = spi_device_transmit(handle->device_handle, &trans);
   SX127X_ERROR_CHECK2(ret, spi_device_transmit);

components/sx127x_driver/sx127x_registers.h

@@ -26,6 +26,6 @@ esp_err_t sx127x_set_sync_word(sx127x_t *handle, uint8_t sync_word);
 
 esp_err_t sx127x_set_crc(sx127x_t *handle, sx127x_crc_t crc);
 
-esp_err_t sx127x_write_fifo(sx127x_t *handle, char *data, size_t data_len);
+esp_err_t sx127x_write_fifo(sx127x_t *handle, const char *data, size_t data_len);
 esp_err_t sx127x_read_fifo(sx127x_t *handle, char *data_out,
                            size_t *data_len_out);