Tell me more ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.
up vote 0 down vote favorite

I am having the same issue as posted here Prolific PL2303 and Ubuntu 12.04 (only in english). The usb to serial adapter worked fine on 11.10 but after upgrade to 12.04 it is not recognized in lusb.

if i connect the device after boot and then run: dmesg | grep tty

i get:

[ 101.305275] usb 2-1.4.4: pl2303 converter now attached to ttyUSB3

seems like it is working fine, but a running the command few seconds later adds the line:

[ 107.788672] pl2303 ttyUSB3: pl2303 converter now disconnected from ttyUSB3

after this the device is no longer detected at all.

any suggestions??

share|improve this question
This question appears to be abandoned and unanswered, could you perhaps add more detail to your question? If this question no longer applies then you can either delete it or answer it yourself if you've solved the problem. Thanks! – Seth Mar 4 at 0:40
@Seth Is the answer here not valuable at all? – Eliah Kagan Mar 4 at 9:18
@Eliah It doesn't answer the question. Although the OP might have solved it in the last comment.. – Seth Mar 4 at 14:26

closed as too localized by Seth, Eric Carvalho, qbi, Jai, vasa1 Mar 4 at 14:55

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, see the FAQ.

1 Answer

up vote 0 down vote

well, I have a same problem... I work around Lazarus with synaser to access the serial on Ubuntu 10.04, after upgrade to 12.04, it's don't work anymore. To make sure that the problem is a Ubuntu version, I try a live cd with other distro and I get the usb to serial working normally again.

look this: after install a gnome-system-tools, I get a users and groups manager. Using this, in advanced settings, I enable access to serial modem and after a new login the usb to serial works again. The solution I get on:

http://ubuntuforums.org/showthread.php?t=1985578&page=2

share|improve this answer
2  
Sorry, this is a bit hard to understand. Are you saying that the answer is to boot a Live CD with some 'other distro', then the hardware bug in Ubuntu is fixed? If yes, what distro (Earlier Ubuntu version, or other OS?) and what do you do besides booting into it and then restarting Ubuntu 12.04? – Tom Brossman Oct 8 '12 at 18:31
Since this looks like a regression I suggest filing a bug, see wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies - it is worth also noting the USB vendor and product ID - the pl2303 USB/serial dongles I have seem to work OK on 12.10, so it may be fixed in 12.10 or it may be a specific device issue. – Colin Ian King Oct 9 '12 at 15:56
1  
I think it is a device specific problem. after switching to a serial adaptor from a different make everything is OK. – eli Oct 9 '12 at 20:17

Not the answer you're looking for? Browse other questions tagged or ask your own question.