Posted on July 12, 2017 at 04:50
Hi,
following scenario:
I use one SD card on my pcb (4 wire sdio) with fatfs and FreeRTOS.
The generated driver init function from ST looks like following (ff_gen_drv.c):
uint8_t FATFS_LinkDriverEx(Diskio_drvTypeDef *drv, char *path, uint8_t lun)
{
uint8_t ret = 1;
uint8_t DiskNum = 0;
if(disk.nbr <= _VOLUMES)
{
disk.is_initialized[disk.nbr] = 0;
disk.drv[disk.nbr] = drv;
disk.lun[disk.nbr] = lun;
DiskNum = disk.nbr++;
path[0] = DiskNum + '0';
path[1] = ':';
path[2] = '/';
path[3] = 0;
ret = 0;
}
return ret;
}�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?
Situation:
I have an exti interrupt on the SD_Detect pin of the socket to dynamically (de-)init the driver whenever the SD card is (un-)plugged.
On unplug, I call:
uint8_t SD_Deinit(void) {
uint8_t retval = FAT_unmount_SD();
return retval | FATFS_UnLinkDriver((const TCHAR*) SD_Path);
}�?�?�?�?
On plugging in, I call (HAL_SDIO_PowerOff/On controls power supply pin pmos of SD socket):
HAL_SDIO_powerOff();
HAL_Delay(200);
HAL_SDIO_powerOn();
HAL_Delay(50);
MX_FATFS_Init(); /* reinit SD card driver as SD card has just been plugged back in */�?�?�?�?�?
Now, what happens is that if I plug the card in and out fast enough, FATFS_LinkDriverEx gets called while the driver is still initialized. This should fail and do nothing due to:
if(disk.nbr <= _VOLUMES)�?
BUT it doesn't because of the <= !! Instead, that must be replace by
if(disk.nbr < _VOLUMES)�?
(as _VOLUMES = 1 in my case).
With that change, the whole procedure works as expected and the code also makes sense. disk.nbr gets incremented by 1 during the init function, after all.
Any optinions?
