USB CDC + MSC composite device STMF4 USB always busy

[JCorn.2]

Hey guys,

I am working on an USB CDC + MSC composite device for the STM32F4. Both, CDC and MSC are working independently in the project.

When I try to use them at the same time MSC is working but CDC is not transmitting anything because USB is always set to busy. Does anybody has an idea how to fix that?

I would like to share the project, since it is really hard to find a USB MSC CDC project in the internet.

[JCorn.2]

Sorry, this attached is the project I am talking about.

To use CDC and MSC set the #define USE_USB_COMPOSITE in usb_device.c and in usbd_desc.c. To use MSC set it to #define USE_USB_MSC and to use CDC just uncommend it.

[JCorn.2]

Here is the composite device config descriptor

static const uint8_t USBD_MSC_CDC_CfgDesc[USB_MSC_CDC_CONFIG_DESC_SIZ] =
{
  0x09,         /* bLength: Configuation Descriptor size */
  USB_DESC_TYPE_CONFIGURATION, /* bDescriptorType: Configuration */
  USB_MSC_CDC_CONFIG_DESC_SIZ, /* wTotalLength: Bytes returned */
  0x00,
  0x03,         /*bNumInterfaces: 3 interface*/
  0x01,         /*bConfigurationValue: Configuration value*/
  0x02,         /*iConfiguration: Index of string descriptor describing the configuration*/
  0xC0,         /*bmAttributes: bus powered and Supports Remote Wakeup */
  0x32,         /*MaxPower 100 mA: this current is used for detecting Vbus*/
  /* 09 bytes */
  
  /********************  Mass Storage interface ********************/
  0x09,   /* bLength: Interface Descriptor size */
  0x04,   /* bDescriptorType: */
  MSC_INTERFACE_IDX,   /* bInterfaceNumber: Number of Interface */
  0x00,   /* bAlternateSetting: Alternate setting */
  0x02,   /* bNumEndpoints*/
  0x08,   /* bInterfaceClass: MSC Class */
  0x06,   /* bInterfaceSubClass : SCSI transparent command set*/
  0x50,   /* nInterfaceProtocol */
  USBD_IDX_INTERFACE_STR,	/* iInterface: */
  /* 09 bytes */
  
  /********************  Mass Storage Endpoints ********************/
  0x07,   /*Endpoint descriptor length = 7*/
  0x05,   /*Endpoint descriptor type */
  MSC_IN_EP,   /*Endpoint address (IN, address 1) */
  0x02,   /*Bulk endpoint type */
  LOBYTE(USB_FS_MAX_PACKET_SIZE),
  HIBYTE(USB_FS_MAX_PACKET_SIZE),
  0x00,   /*Polling interval in milliseconds */
  /* 07 bytes */
  
  0x07,   /*Endpoint descriptor length = 7 */
  0x05,   /*Endpoint descriptor type */
  MSC_OUT_EP,   /*Endpoint address (OUT, address 1) */
  0x02,   /*Bulk endpoint type */
  LOBYTE(USB_FS_MAX_PACKET_SIZE),
  HIBYTE(USB_FS_MAX_PACKET_SIZE),
  0x00,     /*Polling interval in milliseconds*/
  /* 07 bytes */
  
  /******** IAD should be positioned just before the CDC interfaces ******
                  IAD to associate the two CDC interfaces */
  
  0x08, /* bLength */
  0x0B, /* bDescriptorType */
  CDC_INTERFACE_IDX, /* bFirstInterface */
  0x02, /* bInterfaceCount */
  0x02, /* bFunctionClass */
  0x02, /* bFunctionSubClass */
  0x01, /* bFunctionProtocol */
  0x00, /* iFunction (Index of string descriptor describing this function) */
  /* 08 bytes */
  
  /********************  CDC interfaces ********************/
  
  /*Interface Descriptor */
  0x09,   /* bLength: Interface Descriptor size */
  USB_DESC_TYPE_INTERFACE,  /* bDescriptorType: Interface */
  /* Interface descriptor type */
  CDC_INTERFACE_IDX,   /* bInterfaceNumber: Number of Interface */
  0x00,   /* bAlternateSetting: Alternate setting */
  0x01,   /* bNumEndpoints: One endpoints used */
  0x02,   /* bInterfaceClass: Communication Interface Class */
  0x02,   /* bInterfaceSubClass: Abstract Control Model */
  0x01,   /* bInterfaceProtocol: Common AT commands */
  0x01,   /* iInterface: */
  /* 09 bytes */
  
  /*Header Functional Descriptor*/
  0x05,   /* bLength: Endpoint Descriptor size */
  0x24,   /* bDescriptorType: CS_INTERFACE */
  0x00,   /* bDescriptorSubtype: Header Func Desc */
  0x10,   /* bcdCDC: spec release number */
  0x01,
  /* 05 bytes */
  
  /*Call Management Functional Descriptor*/
  0x05,   /* bFunctionLength */
  0x24,   /* bDescriptorType: CS_INTERFACE */
  0x01,   /* bDescriptorSubtype: Call Management Func Desc */
  0x00,   /* bmCapabilities: D0+D1 */
  CDC_INTERFACE_IDX + 1,   /* bDataInterface: 2 */
  /* 05 bytes */
  
  /*ACM Functional Descriptor*/
  0x04,   /* bFunctionLength */
  0x24,   /* bDescriptorType: CS_INTERFACE */
  0x02,   /* bDescriptorSubtype: Abstract Control Management desc */
  0x02,   /* bmCapabilities */
  /* 04 bytes */
  
  /*Union Functional Descriptor*/
  0x05,   /* bFunctionLength */
  0x24,   /* bDescriptorType: CS_INTERFACE */
  0x06,   /* bDescriptorSubtype: Union func desc */
  CDC_INTERFACE_IDX,   /* bMasterInterface: Communication class interface */
  CDC_INTERFACE_IDX + 1,   /* bSlaveInterface0: Data Class Interface */
  /* 05 bytes */
  
  /*Endpoint 2 Descriptor*/
  0x07,                          /* bLength: Endpoint Descriptor size */
  USB_DESC_TYPE_ENDPOINT,        /* bDescriptorType: Endpoint */
  CDC_CMD_EP,                    /* bEndpointAddress */
  0x03,                          /* bmAttributes: Interrupt */
  LOBYTE(CDC_CMD_PACKET_SIZE),   /* wMaxPacketSize: */
  HIBYTE(CDC_CMD_PACKET_SIZE),
  0x10,                          /* bInterval: */
  /* 07 bytes */
  
  /*Data class interface descriptor*/
  0x09,   /* bLength: Endpoint Descriptor size */
  USB_DESC_TYPE_INTERFACE,       /* bDescriptorType: */
  CDC_INTERFACE_IDX + 1,         /* bInterfaceNumber: Number of Interface */
  0x00,                          /* bAlternateSetting: Alternate setting */
  0x02,                          /* bNumEndpoints: Two endpoints used */
  0x0A,                          /* bInterfaceClass: CDC */
  0x00,                          /* bInterfaceSubClass: */
  0x00,                          /* bInterfaceProtocol: */
  0x00,                          /* iInterface: */
  /* 09 bytes */
  
  /*Endpoint OUT Descriptor*/
  0x07,   /* bLength: Endpoint Descriptor size */
  USB_DESC_TYPE_ENDPOINT,        /* bDescriptorType: Endpoint */
  CDC_OUT_EP,                    /* bEndpointAddress */
  0x02,                          /* bmAttributes: Bulk */
  LOBYTE(CDC_DATA_PACKET_SIZE),  /* wMaxPacketSize: */
  HIBYTE(CDC_DATA_PACKET_SIZE),
  0x00,                          /* bInterval: ignore for Bulk transfer */
  /* 07 bytes */
  
  /*Endpoint IN Descriptor*/
  0x07,   /* bLength: Endpoint Descriptor size */
  USB_DESC_TYPE_ENDPOINT,        /* bDescriptorType: Endpoint */
  CDC_IN_EP,                     /* bEndpointAddress */
  0x02,                          /* bmAttributes: Bulk */
  LOBYTE(CDC_DATA_PACKET_SIZE),  /* wMaxPacketSize: */
  HIBYTE(CDC_DATA_PACKET_SIZE),
  0x00,                          /* bInterval */
  /* 07 bytes */
 
};

[Andrey.St.]

Correct usbd_conf.c file in part:

".....

 HAL_PCDEx_SetRxFiFo(pdev->pPCDHandle, 0x80);

 HAL_PCDEx_SetTxFiFo(pdev->pPCDHandle, 0, 0x40);

 HAL_PCDEx_SetTxFiFo(pdev->pPCDHandle, 1, 0x80);

 HAL_PCDEx_SetTxFiFo(pdev->pPCDHandle, 2, 0xC0);

 HAL_PCDEx_SetTxFiFo(pdev->pPCDHandle, 3, 0x100);

.....

"

Give memory for endpoint 2 and 3.