fix(cdc_acm): Fix closing of already closed device

host/class/cdc/usb_host_cdc_acm/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## [Unreleased]
 
 - Added `cdc_acm_host_cdc_desc_get()` function that enables users to get CDC functional descriptors of the device
+- Fixed closing of a CDC device from multiple threads
 
 ## 2.0.2
 

host/class/cdc/usb_host_cdc_acm/cdc_acm_host.c

@@ -845,13 +845,30 @@ esp_err_t cdc_acm_host_close(cdc_acm_dev_hdl_t cdc_hdl)
 
     xSemaphoreTake(p_cdc_acm_obj->open_close_mutex, portMAX_DELAY);
 
-    cdc_dev_t *cdc_dev = (cdc_dev_t *)cdc_hdl;
-
-    // Cancel polling of BULK IN and INTERRUPT IN
+    // Make sure that the device is in the devices list (that it is not already closed)
+    cdc_dev_t *cdc_dev;
+    bool device_found = false;
     CDC_ACM_ENTER_CRITICAL();
+    SLIST_FOREACH(cdc_dev, &p_cdc_acm_obj->cdc_devices_list, list_entry) {
+        if (cdc_dev == (cdc_dev_t *)cdc_hdl) {
+            device_found = true;
+            break;
+        }
+    }
+
+    // Device was not found in the cdc_devices_list; it was already closed, return OK
+    if (!device_found) {
+        CDC_ACM_EXIT_CRITICAL();
+        xSemaphoreGive(p_cdc_acm_obj->open_close_mutex);
+        return ESP_OK;
+    }
+
+    // No user callbacks from this point
     cdc_dev->notif.cb = NULL;
     cdc_dev->data.in_cb = NULL;
     CDC_ACM_EXIT_CRITICAL();
+
+    // Cancel polling of BULK IN and INTERRUPT IN
     if (cdc_dev->data.in_xfer) {
         ESP_ERROR_CHECK(cdc_acm_reset_transfer_endpoint(cdc_dev->dev_hdl, cdc_dev->data.in_xfer));
     }

host/class/cdc/usb_host_cdc_acm/include/usb/cdc_acm_host.h

@@ -188,8 +188,10 @@ esp_err_t cdc_acm_host_open_vendor_specific(uint16_t vid, uint16_t pid, uint8_t
  * @brief Close CDC device and release its resources
  *
  * @note All in-flight transfers will be prematurely canceled.
- * @param cdc_hdl CDC handle obtained from cdc_acm_host_open()
- * @return esp_err_t
+ * @param[in] cdc_hdl CDC handle obtained from cdc_acm_host_open()
+ * @return
+ *   - ESP_OK: Success - device closed
+ *   - ESP_ERR_INVALID_STATE: cdc_hdl is NULL or the CDC driver is not installed
  */
 esp_err_t cdc_acm_host_close(cdc_acm_dev_hdl_t cdc_hdl);
 

host/class/cdc/usb_host_cdc_acm/test/test_cdc_acm_host.c

@@ -177,7 +177,7 @@ TEST_CASE("read_write", "[cdc_acm]")
     TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_open(0x303A, 0x4002, 0, &dev_config, &cdc_dev)); // 0x303A:0x4002 (TinyUSB Dual CDC device)
     TEST_ASSERT_NOT_NULL(cdc_dev);
     cdc_acm_host_desc_print(cdc_dev);
-    vTaskDelay(100);
+    vTaskDelay(10);
 
     TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_data_tx_blocking(cdc_dev, tx_buf, sizeof(tx_buf), 1000));
     TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_data_tx_blocking(cdc_dev, tx_buf, sizeof(tx_buf), 1000));
@@ -566,6 +566,39 @@ TEST_CASE("functional_descriptor", "[cdc_acm]")
     vTaskDelay(20);
 }
 
+/**
+ * @brief Closing procedure test
+ *
+ * -# Close already closed device
+ */
+TEST_CASE("closing", "[cdc_acm]")
+{
+    nb_of_responses = 0;
+    cdc_acm_dev_hdl_t cdc_dev = NULL;
+
+    test_install_cdc_driver();
+
+    const cdc_acm_host_device_config_t dev_config = {
+        .connection_timeout_ms = 500,
+        .out_buffer_size = 64,
+        .event_cb = notif_cb,
+        .data_cb = handle_rx,
+        .user_arg = tx_buf,
+    };
+
+    printf("Opening CDC-ACM device\n");
+    TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_open(0x303A, 0x4002, 0, &dev_config, &cdc_dev)); // 0x303A:0x4002 (TinyUSB Dual CDC device)
+    TEST_ASSERT_NOT_NULL(cdc_dev);
+    vTaskDelay(10);
+
+    TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_close(cdc_dev));
+    printf("Closing already closed device \n");
+    TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_close(cdc_dev));
+    TEST_ASSERT_EQUAL(ESP_OK, cdc_acm_host_uninstall());
+
+    vTaskDelay(20); //Short delay to allow task to be cleaned up
+}
+
 /* Following test case implements dual CDC-ACM USB device that can be used as mock device for CDC-ACM Host tests */
 void run_usb_dual_cdc_device(void);
 TEST_CASE("mock_device_app", "[cdc_acm_device][ignore]")
@@ -576,4 +609,4 @@ TEST_CASE("mock_device_app", "[cdc_acm_device][ignore]")
     }
 }
 
-#endif
+#endif // SOC_USB_OTG_SUPPORTED