I use USB-host MSC on RP2040.
When a USB flash drive is connected, the program stops after 5-60 seconds at the line
while (*pc < PIO_USB_TX_ENCODED_DATA_COMP)
functions
void __not_in_flash_func(pio_usb_bus_usb_transfer)(pio_port_t *pp,
uint8_t *data, uint16_t len)