Merge branch 'fix/twai_legacy_zero_trans' into 'master'

fix(twai): twai legacy driver fixed zero dlc transmit

Closes IDFGH-16321

See merge request espressif/esp-idf!41425

components/driver/test_apps/legacy_twai/main/test_twai_loop_back.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -68,20 +68,22 @@ TEST_CASE("twai_mode_std_no_ack_25kbps", "[twai-loop-back]")
 
     twai_message_t tx_msg = {
         .identifier = 0x123,
-        .data_length_code = 8,
         .data = {0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88},
         .self = true, // Transmitted message will also received by the same node
     };
-    printf("transmit message\r\n");
+    for (int len = 0; len <= 8; len++) {
+        tx_msg.data_length_code = len;
+        printf("TX id %lx len %d\r\n", tx_msg.identifier, tx_msg.data_length_code);
         TEST_ESP_OK(twai_transmit(&tx_msg, pdMS_TO_TICKS(1000)));
 
-    printf("receive message\r\n");
+        twai_message_t rx_msg = {};
-    twai_message_t rx_msg;
         TEST_ESP_OK(twai_receive(&rx_msg, pdMS_TO_TICKS(1000)));
-    TEST_ASSERT_TRUE(rx_msg.data_length_code == 8);
+        printf("RX id %lx len %d\r\n", rx_msg.identifier, rx_msg.data_length_code);
-    for (int i = 0; i < 8; i++) {
+        TEST_ASSERT_EQUAL(rx_msg.data_length_code, tx_msg.data_length_code);
+        for (int i = 0; i < rx_msg.data_length_code; i++) {
             TEST_ASSERT_EQUAL(tx_msg.data[i], rx_msg.data[i]);
         }
+    }
 
     TEST_ESP_OK(twai_stop());
     TEST_ESP_OK(twai_driver_uninstall());

components/driver/twai/twai.c

@@ -738,7 +738,7 @@ esp_err_t twai_transmit_v2(twai_handle_t handle, const twai_message_t *message,
         .frame = {
             .header = &header,
             .buffer = (uint8_t *)message->data,
-            .buffer_len = TWAI_FRAME_MAX_LEN,
+            .buffer_len = message->data_length_code,
         },
         .config.retry_cnt = message->ss ? 0 : -1,
         .config.loopback = message->self,

components/esp_driver_twai/esp_twai_onchip.c

@@ -589,7 +589,8 @@ static esp_err_t _node_queue_tx(twai_node_handle_t node, const twai_frame_t *fra
 #if !SOC_TWAI_SUPPORT_FD
     ESP_RETURN_ON_FALSE_ISR(!frame->header.fdf || frame->buffer_len <= TWAI_FRAME_MAX_LEN, ESP_ERR_INVALID_ARG, TAG, "fdf flag or buffer_len not supported");
 #endif
-    ESP_RETURN_ON_FALSE_ISR(frame->buffer_len <= (frame->header.fdf ? TWAIFD_FRAME_MAX_LEN : TWAI_FRAME_MAX_LEN), ESP_ERR_INVALID_ARG, TAG, "illegal transfer length (buffer_len %ld)", frame->buffer_len);
+    ESP_RETURN_ON_FALSE_ISR((frame->header.dlc <= TWAIFD_FRAME_MAX_DLC) && \
+                            (frame->buffer_len <= (frame->header.fdf ? TWAIFD_FRAME_MAX_LEN : TWAI_FRAME_MAX_LEN)), ESP_ERR_INVALID_ARG, TAG, "illegal transfer length (buffer_len %ld)", frame->buffer_len);
     ESP_RETURN_ON_FALSE_ISR((!frame->header.brs) || (twai_ctx->valid_fd_timing), ESP_ERR_INVALID_ARG, TAG, "brs can't be used without config data_timing");
     ESP_RETURN_ON_FALSE_ISR(!twai_ctx->hal->enable_listen_only, ESP_ERR_NOT_SUPPORTED, TAG, "node is config as listen only");
     ESP_RETURN_ON_FALSE_ISR(atomic_load(&twai_ctx->state) != TWAI_ERROR_BUS_OFF, ESP_ERR_INVALID_STATE, TAG, "node is bus off");

components/esp_driver_twai/test_apps/test_twai/main/test_twai_common.cpp

@@ -720,3 +720,64 @@ TEST_CASE("twai send from ISR context (loopback)", "[twai]")
 
     printf("ISR send test passed!\n");
 }
+
+static IRAM_ATTR bool test_dlc_range_cb(twai_node_handle_t handle, const twai_rx_done_event_data_t *edata, void *user_ctx)
+{
+    twai_frame_t *rx_frame = (twai_frame_t *)user_ctx;
+    if (ESP_OK == twai_node_receive_from_isr(handle, rx_frame)) {
+        esp_rom_printf(DRAM_STR("RX len %d %s\n"), rx_frame->header.dlc, rx_frame->buffer);
+    }
+    return false;
+}
+
+TEST_CASE("twai dlc range test", "[twai]")
+{
+    twai_node_handle_t node_hdl;
+    twai_onchip_node_config_t node_config = {};
+    node_config.io_cfg.tx = TEST_TX_GPIO;
+    node_config.io_cfg.rx = TEST_TX_GPIO; // Using same pin for test without transceiver
+    node_config.bit_timing.bitrate = 800000;
+    node_config.tx_queue_depth = TEST_FRAME_NUM;
+    node_config.flags.enable_loopback = true;
+    node_config.flags.enable_self_test = true;
+
+    TEST_ESP_OK(twai_new_node_onchip(&node_config, &node_hdl));
+
+    uint8_t rx_buffer[TWAI_FRAME_MAX_LEN] = {0};
+    twai_frame_t rx_frame = {};
+    rx_frame.buffer = rx_buffer;
+    rx_frame.buffer_len = sizeof(rx_buffer);
+
+    twai_event_callbacks_t user_cbs = {};
+    user_cbs.on_rx_done = test_dlc_range_cb;
+    TEST_ESP_OK(twai_node_register_event_callbacks(node_hdl, &user_cbs, &rx_frame));
+    TEST_ESP_OK(twai_node_enable(node_hdl));
+
+    twai_frame_t tx_frame = {};
+    tx_frame.header.id = TWAI_STD_ID_MASK;
+    tx_frame.buffer = (uint8_t *)"hi esp32";
+    for (int len = 0; len < 2 * 9; len++) { // [0:8] is 9 times
+        if (len < 9) {
+            tx_frame.buffer_len = len;
+            tx_frame.header.dlc = 0;
+        } else {
+            tx_frame.buffer_len = 0;
+            tx_frame.header.dlc = len % 9;
+        }
+        TEST_ESP_OK(twai_node_transmit(node_hdl, &tx_frame, 100));
+        TEST_ESP_OK(twai_node_transmit_wait_all_done(node_hdl, -1));
+        TEST_ASSERT_EQUAL(len % 9, rx_frame.header.dlc);
+        memset(rx_buffer, 0, sizeof(rx_buffer));
+    }
+
+    tx_frame.buffer_len = 9;
+    tx_frame.header.dlc = 0;
+    TEST_ESP_ERR(twai_node_transmit(node_hdl, &tx_frame, 0), ESP_ERR_INVALID_ARG);
+
+    tx_frame.buffer_len = 0;
+    tx_frame.header.dlc = TWAIFD_FRAME_MAX_DLC + 1;
+    TEST_ESP_ERR(twai_node_transmit(node_hdl, &tx_frame, 0), ESP_ERR_INVALID_ARG);
+
+    TEST_ESP_OK(twai_node_disable(node_hdl));
+    TEST_ESP_OK(twai_node_delete(node_hdl));
+}