CH341 Kernel module no longer working after running updates

ninjai117 · 2016-07-23 19:51:19

I use one of those chinese USB to serial adapters to console into some Cisco gear I have. It used to work great, I could minicom into my devices with no issues. One day last week I ran a pacman -Syyu, then rebooted, now I can no longer access the console through /dev/ttyUSB0. On the exact same machine I can access the gear fine in Windows. Just no longer in Arch.

I have verified the settings in minicom are correct. I've also tried picocom and putty to no avail. It's something lower level.

I can see that the module is loaded:

[steve@steve-arch ~]$ lsmod | grep ch341
ch341                  16384  0
usbserial              40960  1 ch341
usbcore               200704  9 ch341,usbserial,ohci_hcd,ohci_pci,ehci_hcd,ehci_pci,usbhid,xhci_hcd,xhci_pci

No matter what keys I press I get no response from my terminal:

Welcome to minicom 2.7

OPTIONS: I18n 
Compiled on Sep  6 2015, 19:49:19.
Port /dev/ttyUSB0, 12:49:06

Press CTRL-A Z for help on special keys






























CTRL-A Z for help | 9600 8N1 | NOR | Minicom 2.7 | VT102 | Offline | ttyUSB0

I can see the device is attached:

[steve@steve-arch ~]$ lsusb
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 004: ID 046d:c069 Logitech, Inc. M-U0007 [Corded Mouse M500]
Bus 006 Device 006: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter                   <-----------------------Right here
Bus 006 Device 002: ID 0d62:001d Darfon Electronics Corp. 
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
[steve@steve-arch ~]$

I really don't see how this could be anything other than something to do with the kernel at this point, unless I'm missing something very stupid. I have checked the settings 10 times over (which I never changed from when it was working) and they are correct. Same settings work in Windows with the same setup. Any ideas? I would really like to be able to configure my gear from Arch again instead of having to boot back into windows.

Last edited by ninjai117 (2016-07-23 19:52:48)

R00KIE · 2016-07-23 20:20:43

If it was working before and now it isn't then it's probably a regression and you should complain upstream.

That said, ch341 adapters are not the best around, sure they are cheap but they cut all possible corners. On top of that there are many versions, some of which never worked on linux, I am the lucky owner of one of such versions.

ninjai117 · 2016-07-23 20:40:24

How would I put my issue upstream?

What adapters are solid and not cheap pieces of junk? Sad that this has no issues in windows

R00KIE · 2016-07-23 23:14:03

ninjai117 wrote:

How would I put my issue upstream?

You would need to register here and open a bug report.

ninjai117 wrote:

What adapters are solid and not cheap pieces of junk? Sad that this has no issues in windows

I will not recommend anything specific [1], all I can say is do your research well before you buy, and buy preferably from somewhere you can easily return it if it doesn't work. Another thing is avoid cheap stuff, it's most probably made with counterfeit chips and/or cutting corners.

All that said, if your converter used to work properly, all it should take is a software fix to make it work again.

[1] https://wiki.archlinux.org/index.php/Co … n_requests

Arch Linux

#1 2016-07-23 19:51:19

CH341 Kernel module no longer working after running updates

#2 2016-07-23 20:20:43

Re: CH341 Kernel module no longer working after running updates

#3 2016-07-23 20:40:24

Re: CH341 Kernel module no longer working after running updates

#4 2016-07-23 23:14:03

Re: CH341 Kernel module no longer working after running updates

Board footer