USB-SERIAL HAS STOPPED WORKING

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jwinship
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Joined: 2014/09/24 15:08:31

USB-SERIAL HAS STOPPED WORKING

Post by jwinship » 2014/10/03 01:38:01

Hi Guys.

If anyine could help me I'd appreciate. I've just deleted windows from my laptop and installed CentOS 7. I used to be able to connect to a router with a USB-serial via Putty. I am constantly updating programs, but not putty. Today, whilst continuing my studies, I attempted to open a serial connection on putty (/dev/ttyUSB[0,1]) and it says 'unable to open serial port'. The funny thing is that I have a windows 7 virtual machine with putty installed and the USB-serial adaptor works. I have tried to re-install Putty to no avail!


[root@CentOS7-HPldomain jwilson]# lsusb | grep -i serial
Bus 003 Device 003: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter


[root@CentOS7-HPldomain jwilson]# dmesg | grep -i ch
[ 1662.153052] usb 3-1: new full-speed USB device number 3 using xhci_hcd
[ 1662.165299] usb 3-1: New USB device found, idVendor=1a86, idProduct=7523
[ 1662.165305] usb 3-1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 1662.165308] usb 3-1: Product: USB2.0-Ser!
[ 1662.167246] usb 3-1: ch341-uart converter now attached to ttyUSB1
[ 2785.006241] ch341-uart ttyUSB1: ch341-uart converter now disconnected from ttyUSB1

[root@CentOS7-HPldomain ch341_drv]# lsmod | grep -i ch341
ch341 14072 1

I'm new to linux and if someone could help me I would really appreciate it. Thanks in advance.

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TrevorH
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Re: USB-SERIAL HAS STOPPED WORKING

Post by TrevorH » 2014/10/03 02:00:04

Try running modprobe -r usbserial then modprobe usbserial vendor=0x1a86 product=0x7523

If that works then create a new file in /etc/modprobe.d called something like usbserial.conf and put this in it

Code: Select all

options usbserial vendor=0x1a86 product=0x7523
and then it will become permanent.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

jwinship
Posts: 23
Joined: 2014/09/24 15:08:31

Re: USB-SERIAL HAS STOPPED WORKING

Post by jwinship » 2014/10/03 13:31:45

Thanks for your reply. Here are the results:

[root@CentOS7-HPldomain transmission-2.84]# modprobe -r usbserial
modprobe: FATAL: Module usbserial is builtin.
[root@CentOS7-HPldomain transmission-2.84]#

I tried the other command and unfortunately it didn't work. Thanks anyway. Any clues as to what the problem might be?

Much appreciated. Cheers!

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TrevorH
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Re: USB-SERIAL HAS STOPPED WORKING

Post by TrevorH » 2014/10/03 14:15:41

Oh, brilliant move Redhat :-(

OK, next attempt is to pass the same parameters via the kernel command line. You can edit that by pressing Esc when the machine first starts to boot and you see the grub2 prompt or you can edit /boot/grub2/grub.cfg and locate the correct "linux16" line there and add the parameters to that. They are in a slightly different format and you'd now need to use usbserial.vendor=0x1a86 and usbserial.product=0x7523
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

jwinship
Posts: 23
Joined: 2014/09/24 15:08:31

Re: USB-SERIAL HAS STOPPED WORKING

Post by jwinship » 2014/10/08 19:27:24

Hi Trevor.

Thanks for your time and sorry for the late reply. Been travelling.

I can't seem to find the "linux 16" in the grub.cfg. I have attached a copy of my grub.cfg. I apologise for being a newbie. Is it possible to direct me to which line it is. :)

I really appreciate your time and thanks in advance.
For-troubleshooting-grub.cfg.txt
grub.cfg
(4.94 KiB) Downloaded 306 times

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TrevorH
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Location: Brighton, UK

Re: USB-SERIAL HAS STOPPED WORKING

Post by TrevorH » 2014/10/08 19:42:05

Yours are linuxefi lines
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

jwinship
Posts: 23
Joined: 2014/09/24 15:08:31

Re: USB-SERIAL HAS STOPPED WORKING

Post by jwinship » 2014/10/09 19:37:38

Thanks Trevor.

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