fix(host/cdc_acm): Fix CTRL transfer size for devices with small MaxP…

…acketSize0

Closes espressif/esp-idf#14345

host/class/cdc/usb_host_cdc_acm/CHANGELOG.md

@@ -1,3 +1,7 @@
+## [Unreleased]
+
+- Fixed Control transfer allocation size for too small EP0 Max Packet Size (https://github.com/espressif/esp-idf/issues/14345)
+
 ## 2.0.3
 
 - Added `cdc_acm_host_cdc_desc_get()` function that enables users to get CDC functional descriptors of the device

host/class/cdc/usb_host_cdc_acm/cdc_acm_host.c

@@ -24,11 +24,15 @@ static const char *TAG = "cdc_acm";
 // bDeviceClass = 0xEF (Miscellaneous Device Class), bDeviceSubClass = 0x02 (Common Class), bDeviceProtocol = 0x01 (Interface Association Descriptor),
 // or when bDeviceClass, bDeviceSubClass, and bDeviceProtocol are 0x00 (Null class code triple), as per https://www.usb.org/defined-class-codes, "Base Class 00h (Device)" section
 // @see USB Interface Association Descriptor: Device Class Code and Use Model rev 1.0, Table 1-1
-#define USB_SUBCLASS_NULL        0x00
+#define USB_SUBCLASS_NULL          0x00
 #define USB_SUBCLASS_COMMON        0x02
-#define USB_PROTOCOL_NULL    0x00
+#define USB_PROTOCOL_NULL          0x00
 #define USB_DEVICE_PROTOCOL_IAD    0x01
 
+// Control transfer constants
+#define CDC_ACM_CTRL_TRANSFER_SIZE (64)   // All standard CTRL requests and responses fit in this size
+#define CDC_ACM_CTRL_TIMEOUT_MS    (5000) // Every CDC device should be able to respond to CTRL transfer in 5 seconds
+
 // CDC-ACM spinlock
 static portMUX_TYPE cdc_acm_lock = portMUX_INITIALIZER_UNLOCKED;
 #define CDC_ACM_ENTER_CRITICAL()   portENTER_CRITICAL(&cdc_acm_lock)
@@ -566,10 +570,8 @@ static esp_err_t cdc_acm_transfers_allocate(cdc_dev_t *cdc_dev, const usb_ep_des
     }
 
     // 2. Setup control transfer
-    usb_device_info_t dev_info;
-    ESP_ERROR_CHECK(usb_host_device_info(cdc_dev->dev_hdl, &dev_info));
     ESP_GOTO_ON_ERROR(
-        usb_host_transfer_alloc(dev_info.bMaxPacketSize0, 0, &cdc_dev->ctrl_transfer),
+        usb_host_transfer_alloc(CDC_ACM_CTRL_TRANSFER_SIZE, 0, &cdc_dev->ctrl_transfer),
         err, TAG,);
     cdc_dev->ctrl_transfer->timeout_ms = 1000;
     cdc_dev->ctrl_transfer->bEndpointAddress = 0;
@@ -1235,7 +1237,7 @@ esp_err_t cdc_acm_host_send_custom_request(cdc_acm_dev_hdl_t cdc_hdl, uint8_t bm
     esp_err_t ret;
 
     // Take Mutex and fill the CTRL request
-    BaseType_t taken = xSemaphoreTake(cdc_dev->ctrl_mux, pdMS_TO_TICKS(5000));
+    BaseType_t taken = xSemaphoreTake(cdc_dev->ctrl_mux, pdMS_TO_TICKS(CDC_ACM_CTRL_TIMEOUT_MS));
     if (!taken) {
         return ESP_ERR_TIMEOUT;
     }
@@ -1258,7 +1260,7 @@ esp_err_t cdc_acm_host_send_custom_request(cdc_acm_dev_hdl_t cdc_hdl, uint8_t bm
         usb_host_transfer_submit_control(p_cdc_acm_obj->cdc_acm_client_hdl, cdc_dev->ctrl_transfer),
         unblock, TAG, "CTRL transfer failed");
 
-    taken = xSemaphoreTake((SemaphoreHandle_t)cdc_dev->ctrl_transfer->context, pdMS_TO_TICKS(5000)); // This is a fixed timeout. Every CDC device should be able to respond to CTRL transfer in 5 seconds
+    taken = xSemaphoreTake((SemaphoreHandle_t)cdc_dev->ctrl_transfer->context, pdMS_TO_TICKS(CDC_ACM_CTRL_TIMEOUT_MS));
     if (!taken) {
         // Transfer was not finished, error in USB LIB. Reset the endpoint
         cdc_acm_reset_transfer_endpoint(cdc_dev->dev_hdl, cdc_dev->ctrl_transfer);