FTDI hotplug

Toad39 · 2020-11-30 02:42:16

Hello,

I am trying to work on a Cisco 4948 with my Thinkpad X1 Carbon, 1st Generation. This doesn't have a serial port, so I bought a USB to serial-RJ45 adapter. Before rebooting, it seems like it still recognizes it. Here are the dmesg logs:

[19031.585151] usb 1-1.2: new full-speed USB device number 7 using ehci-pci
[19031.693813] usb 1-1.2: New USB device found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
[19031.693816] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[19031.693818] usb 1-1.2: Product: FT232R USB UART
[19031.693820] usb 1-1.2: Manufacturer: FTDI
[19031.693822] usb 1-1.2: SerialNumber: A9JIL5R3
[19031.696723] ftdi_sio 1-1.2:1.0: FTDI USB Serial Device converter detected
[19031.696764] usb 1-1.2: Detected FT232RL
[19031.699247] usb 1-1.2: FTDI USB Serial Device converter now attached to ttyUSB0

A list of /dev has only /dev/ttyS[0123], none of which work: http://ix.io/2FZx.

After rebooting, I have a new device, /dev/ttyUSB0, that successfully communicates with my switch. Notice that this only worked after a reboot. My suspect is that udev is not hot-plugging it. Is there a way to enable it?

Thanks for the help.

Trilby · 2020-11-30 03:08:37

Was this only a one time issue, or has it replicated? It's far more likely that you simply hadn't rebooted since your last kernel upgrade so the needed module wasn't present for loading.

Also that list you posted does indeed include ttyUSB0 which seems to contradict your claims.

Last edited by Trilby (2020-11-30 03:10:28)

Toad39 · 2020-11-30 23:26:39

@Trilby

Was this only a one time issue, or has it replicated?

This happens every time.

Also that list you posted does indeed include ttyUSB0 which seems to contradict your claims.

The list I posted was before the reboot. After the reboot, ttyUSB0 is there.

Arch Linux

#1 2020-11-30 02:42:16

FTDI hotplug

#2 2020-11-30 03:08:37

Re: FTDI hotplug

#3 2020-11-30 23:26:39

Re: FTDI hotplug

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