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startx causes USB devices to fail

Posted: Fri Jun 22, 2012 1:20 pm
by keithsuddick
I've been battling with my Raspberry Pi for a few weeks now, and, after replacing a hub (which was reported on as problematic), a wi-fi dongle (which refused to be recognised even by lsusb) and a keyboard (which just seemed to cause problems when used with any hub) I've now spent £90 on this $35 computer and it still doesn't work... well not fully...

I now have a wi-fi dongle (D-Link WGA-140), keyboard and mouse connected to a 4 port powered hub (the 7 Day Shop One mentioned on and this hub is the only device connected to the Pi's USB ports.

Using the Debian Squeeze image with updated firmware, the Pi boots up fine. I've got wi-fi working, installed and ran rpi-update successfully, I can log-on fine, I can even ssh and sftp into it from other machines - everything from the command line seems fine. After a minute or so no further messages are listed by dmesg.

As soon as I start lxde with startx, the wi-fi connection drops, the keyboard stops working and the mouse works sporadically.

I've managed to get back out of lxde, and the keyboard started working again, but I can't get the wi-fi connection back. I did manage to dump the output of dmesg to a file and it shows constant messages from the time lxde starts (at 825.x in the file I'm attaching) to the time I dumped the file.

Any suggestions would be gratefully received...

The forum won't let me upload an attachment so I've put the dmesg output here...

Re: startx causes USB devices to fail

Posted: Fri Jun 22, 2012 1:50 pm
by RaTTuS
your HUB is reporting a lot of errors
1 remove the wireless , and mouse and hub
plug in a wired NIC amd keyboard
does it boot happy ?

sudo tail -f /var/log/syslog &
remove keyboard plug in hub
plug bits in one by one and see when your get errors
It could be down to poor power
or your hub sending power back to the rpi and fighting

others will have more info/help

Re: startx causes USB devices to fail

Posted: Fri Jun 22, 2012 2:02 pm
by marsman2020
This could be a software issue, see

Re: startx causes USB devices to fail

Posted: Fri Jun 22, 2012 3:22 pm
by keithsuddick
- RaTTuS

Thanks for the suggestions, as it happened I decided to image a new SD card just in case something had been corrupted so I *had* to go back to using the wired ethernet link to get the necessary firmware etc and there did not seem to be any problems, I could start lxde and the mouse, keyboard and network all continued to work fine. (I reinstalled all the firmware and configuration files and when I switched back to wifi the problems reappeared - no network, sporadic mouse and keyboard operation on starting lxde.)

I've checked the TP1-TP2 voltage several times now and it seems to be reasonably stable at 4.77-4.81 volts.

- marsman2020

Thanks for pointing me at the github postings - interesting to see this may be a more widespread problem, I just wish I was more knowledgeable in order to help pin it down.