STM32 USB OTG HOST Library hangs trying to create file with FatFs - c

Question

I am trying to create a file with FatFs on USB flash, but my f_open call trying to read boot sector for first time file system mount hangs on this function.
DRESULT disk_read (
BYTE drv, /* Physical drive number (0) */
BYTE *buff, /* Pointer to the data buffer to store read data */
DWORD sector, /* Start sector number (LBA) */
BYTE count /* Sector count (1..255) */
)
{
BYTE status = USBH_MSC_OK;
if (drv || !count) return RES_PARERR;
if (Stat & STA_NOINIT) return RES_NOTRDY;
if(HCD_IsDeviceConnected(&USB_OTG_Core))
{
do
{
status = USBH_MSC_Read10(&USB_OTG_Core, buff,sector,512 * count);
USBH_MSC_HandleBOTXfer(&USB_OTG_Core ,&USB_Host);
if(!HCD_IsDeviceConnected(&USB_OTG_Core))
{
return RES_ERROR;
}
}
while(status == USBH_MSC_BUSY ); // Loop which create hanging state
}
if(status == USBH_MSC_OK)
return RES_OK;
return RES_ERROR;
}
The main problem is the loop which creates hanging state
while(status == USBH_MSC_BUSY );
So I do not know what to do to avoid this. Using debugger I discover that state is caused by parameter CmdStateMachine of structure USBH_MSC_BOTXferParam, type USBH_BOTXfer_TypeDef is equal CMD_UNINITIALIZED_STATE which actually cause miss up of switch statement of USBH_MSC_Read10 function.
/**
* #brief USBH_MSC_Read10
* Issue the read command to the device. Once the response received,
* it updates the status to upper layer
* #param dataBuffer : DataBuffer will contain the data to be read
* #param address : Address from which the data will be read
* #param nbOfbytes : NbOfbytes to be read
* #retval Status
*/
uint8_t USBH_MSC_Read10(USB_OTG_CORE_HANDLE *pdev,
uint8_t *dataBuffer,
uint32_t address,
uint32_t nbOfbytes)
{
uint8_t index;
static USBH_MSC_Status_TypeDef status = USBH_MSC_BUSY;
uint16_t nbOfPages;
status = USBH_MSC_BUSY;
if(HCD_IsDeviceConnected(pdev))
{
switch(USBH_MSC_BOTXferParam.CmdStateMachine)
{
case CMD_SEND_STATE:
/*Prepare the CBW and relevant field*/
USBH_MSC_CBWData.field.CBWTransferLength = nbOfbytes;
USBH_MSC_CBWData.field.CBWFlags = USB_EP_DIR_IN;
USBH_MSC_CBWData.field.CBWLength = CBW_LENGTH;
USBH_MSC_BOTXferParam.pRxTxBuff = dataBuffer;
for(index = CBW_CB_LENGTH; index != 0; index--)
{
USBH_MSC_CBWData.field.CBWCB[index] = 0x00;
}
USBH_MSC_CBWData.field.CBWCB[0] = OPCODE_READ10;
/*logical block address*/
USBH_MSC_CBWData.field.CBWCB[2] = (((uint8_t*)&address)[3]);
USBH_MSC_CBWData.field.CBWCB[3] = (((uint8_t*)&address)[2]);
USBH_MSC_CBWData.field.CBWCB[4] = (((uint8_t*)&address)[1]);
USBH_MSC_CBWData.field.CBWCB[5] = (((uint8_t*)&address)[0]);
/*USBH_MSC_PAGE_LENGTH = 512*/
nbOfPages = nbOfbytes/ USBH_MSC_PAGE_LENGTH;
/*Tranfer length */
USBH_MSC_CBWData.field.CBWCB[7] = (((uint8_t *)&nbOfPages)[1]) ;
USBH_MSC_CBWData.field.CBWCB[8] = (((uint8_t *)&nbOfPages)[0]) ;
USBH_MSC_BOTXferParam.BOTState = USBH_MSC_SEND_CBW;
/* Start the transfer, then let the state machine
manage the other transactions */
USBH_MSC_BOTXferParam.MSCState = USBH_MSC_BOT_USB_TRANSFERS;
USBH_MSC_BOTXferParam.BOTXferStatus = USBH_MSC_BUSY;
USBH_MSC_BOTXferParam.CmdStateMachine = CMD_WAIT_STATUS;
status = USBH_MSC_BUSY;
break;
case CMD_WAIT_STATUS:
if((USBH_MSC_BOTXferParam.BOTXferStatus == USBH_MSC_OK) && \
(HCD_IsDeviceConnected(pdev)))
{
/* Commands successfully sent and Response Received */
USBH_MSC_BOTXferParam.CmdStateMachine = CMD_SEND_STATE;
status = USBH_MSC_OK;
}
else if (( USBH_MSC_BOTXferParam.BOTXferStatus == USBH_MSC_FAIL ) && \
(HCD_IsDeviceConnected(pdev)))
{
/* Failure Mode */
USBH_MSC_BOTXferParam.CmdStateMachine = CMD_SEND_STATE;
}
else if ( USBH_MSC_BOTXferParam.BOTXferStatus == USBH_MSC_PHASE_ERROR )
{
/* Failure Mode */
USBH_MSC_BOTXferParam.CmdStateMachine = CMD_SEND_STATE;
status = USBH_MSC_PHASE_ERROR;
}
else
{
/* Wait for the Commands to get Completed */
/* NO Change in state Machine */
}
break;
default:
break;
}
}
return status;
}
Here is USBH_BOTXfer_TypeDef type declaration;
typedef struct _BOTXfer
{
uint8_t MSCState;
uint8_t MSCStateBkp;
uint8_t MSCStateCurrent;
uint8_t CmdStateMachine;
uint8_t BOTState;
uint8_t BOTStateBkp;
uint8_t* pRxTxBuff;
uint16_t DataLength;
uint8_t BOTXferErrorCount;
uint8_t BOTXferStatus;
} USBH_BOTXfer_TypeDef;
During the debug I discover that all fields of it is 0x00.
Here are my FatFs calls
int main(void)
{
FATFS Fat;
FIL file;
FRESULT fr;
RCC->AHB1ENR |= RCC_AHB1ENR_GPIODEN;
/* Enable SWO output */
DBGMCU->CR = 0x00000020;
GPIOD->MODER=0x55000000;
GPIOD->OTYPER = 0x00000000;
GPIOD->OSPEEDR = 0x00000001;
while(1)
{
if (!USB_MSC_IsInitialized())
{
USB_MSC_Initialize();
}
if (USB_MSC_IsConnected())
{
GPIOD->ODR = (1 << 15);
disk_initialize(0);
fr = f_mount(0, &Fat);
if(fr == FR_OK)
{
fr = f_open(&file,"0:DP_lab8.pdf",(FA_CREATE_ALWAYS | FA_WRITE));
if (fr == FR_OK)
{
f_close(&file);
}
f_mount(0, NULL);
}
}
else
{
GPIOD->ODR = (1 << 14);
}
USB_MSC_Main();
}
}
USB_MSC_IsConnected function is:
int USB_MSC_IsConnected(void)
{
if (g_USB_MSC_HostStatus == USB_DEV_NOT_SUPPORTED)
{
USB_MSC_Uninitialize();
}
return !(g_USB_MSC_HostStatus == USB_DEV_DETACHED ||
g_USB_MSC_HostStatus == USB_HOST_NO_INIT ||
g_USB_MSC_HostStatus == USB_DEV_NOT_SUPPORTED);
}
And device states are:
typedef enum
{
USB_HOST_NO_INIT = 0, /* USB interface not initialized */
USB_DEV_DETACHED, /* no device connected */
USB_SPEED_ERROR, /* unsupported USB speed */
USB_DEV_NOT_SUPPORTED, /* unsupported device */
USB_DEV_WRITE_PROTECT, /* device is write protected */
USB_OVER_CURRENT, /* overcurrent detected */
USB_DEV_CONNECTED /* device connected and ready */
} USB_HostStatus;
The value of g_USB_MSC_HostStatus is received by standard USB HOST user callbacks.

Answer 1

I think it is a bug in ST host library. I've hunted it down, as my usb host was unable to pass enumeration stage. After a fix the stack is Ok.
There is union _USB_Setup in usbh_def.h file in "STM32Cube/Repository/STM32Cube_FW_F7_V1.13.0/Middlewares/ST/STM32_USB_Host_Library/Core/Inc" (any chip, not only F7, any version, not only V1.13.0). It has uint16_t bmRequestType and uint16_t bRequest. These two fileds must be uint8_t as of USB specs. Fixing this issue made usb host go as needed. Enumeration stage passes ok, and all other stages as well.