USB Mass storage and SD CARD on STM32L4R9

[LVall.1]

Hi,

I am using the STEVAL-STWINKT1 board with STM32L4R9 MCU. I want the USB work as Mass Storage linked to 4GB SD Card, connected by SDMMC 4 bits peripheral. SD Card is formated in FAT mode. Dare are read throught FAT_FS Middleware.

It is currently working but once I connect USB to PC it takes almost 1 minute to see it on my computer device manager as a 4 GB mass storage.

The code in usbd_storage_if. has been modified as it follows

extern SD_HandleTypeDef hsd1; 
 
int8_t STORAGE_GetCapacity_FS(uint8_t lun, uint32_t *block_num, uint16_t *block_size) 
{ 
 /* USER CODE BEGIN 3 */ 
 *block_num = hsd1.SdCard.LogBlockNbr; 
 *block_size = hsd1.SdCard.LogBlockSize; 
 //*block_num = STORAGE_BLK_NBR; 
 //*block_size = STORAGE_BLK_SIZ; 
 return (USBD_OK); 
 /* USER CODE END 3 */ 
}
 
int8_t STORAGE_Read_FS(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len) 
{ 
 /* USER CODE BEGIN 6 */ 
 HAL_SD_ReadBlocks(&hsd1, buf, blk_addr, (uint32_t) blk_len, 10); 
 return (USBD_OK); 
 /* USER CODE END 6 */ 
}
 
int8_t STORAGE_Write_FS(uint8_t lun, uint8_t *buf, uint32_t blk_addr, uint16_t blk_len) 
{ 
 /* USER CODE BEGIN 7 */ 
 HAL_SD_WriteBlocks(&hsd1, buf, blk_addr, (uint32_t) blk_len, 10); 
 return (USBD_OK); 
 /* USER CODE END 7 */ 
}

In debug mode, I notice the information about SD card and block size are always null. They are populated after several seconds.

Do you have any suggestions to get it faster, please?

Thank you