我将 FTDI RS 232 连接到装有 Ubuntu 16.04 的英特尔 UpBoard。但运行时dmesg | grep tty出现以下错误：
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.15.0-37-generic root=UUID=77afd5d3-427e-4dc4-bea1-5996538070a6 ro console=tty0 console=ttyS0,115200n8 quiet splash vt.handoff=7
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.15.0-37-generic root=UUID=77afd5d3-427e-4dc4-bea1-5996538070a6 ro console=tty0 console=ttyS0,115200n8 quiet splash vt.handoff=7
[ 0.000000] console [tty0] enabled
[ 0.000000] console [ttyS0] enabled
[ 2.391092] 00:01: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[ 4.496363] 8086228A:00: ttyS4 at MMIO 0xa171b000 (irq = 39, base_baud = 2764800) is a 16550A
[ 399.845794] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB0
[ 838.150554] ftdi_sio ttyUSB0: error from flowcontrol urb
[ 838.163075] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[ 1011.239845] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB1
[ 1114.578178] ftdi_sio ttyUSB1: FTDI USB Serial Device converter now disconnected from ttyUSB1
[ 1139.601397] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB1
[ 1663.918667] ftdi_sio ttyUSB1: FTDI USB Serial Device converter now disconnected from ttyUSB1
[ 1920.236846] usb 1-4.3: FTDI USB Serial Device converter now attached to ttyUSB1
[ 2608.217508] ftdi_sio ttyUSB1: FTDI USB Serial Device converter now disconnected from ttyUSB1
[ 2640.032168] usb 1-7.1: FTDI USB Serial Device converter now attached to ttyUSB1
[ 5900.659443] ftdi_sio ttyUSB1: usb_serial_generic_read_bulk_callback - urb stopped: -32
[ 5900.676989] ftdi_sio ttyUSB1: usb_serial_generic_read_bulk_callback - urb stopped: -32
[ 5900.876198] ftdi_sio ttyUSB1: error from flowcontrol urb
[ 5900.888991] ftdi_sio ttyUSB1: FTDI USB Serial Device converter now disconnected from ttyUSB1
[ 5935.790088] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB2
[ 6465.257081] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[ 6470.193102] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB2
[ 6725.954447] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[ 7338.643022] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB2
[ 7470.977015] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[ 8103.098825] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB2
[ 8403.982971] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[ 8597.955152] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB2
[ 8793.105429] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[10342.579878] usb 1-4: FTDI USB Serial Device converter now attached to ttyUSB2
[11941.177073] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[12755.096801] usb 1-7.1: FTDI USB Serial Device converter now attached to ttyUSB2
[12851.533357] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
[13018.524419] usb 1-7.1: FTDI USB Serial Device converter now attached to ttyUSB2
有人能帮我解决这个问题吗？