Red Hat Bugzilla – Bug 967361
Fedora hangs on USB to serial converter
Last modified: 2013-05-29 07:29:06 EDT
This is probably the wrong component, but as close as I could figure out Description of problem: System hangs with USB to serial converter Version-Release number of selected component (if applicable): raspberrypi-kernel-3.6.11-2.20130205gitc5cb0b5.rpfr18.armv5tel How reproducible: Reproduceable Steps to Reproduce: 1. Plug in USB-Serial converter based on Future Technology chip (0403:f448) 2. Start gtkterm 3. Select ttyUSBx associated with converter 4. Click Ok Actual results: Entire system hangs as soon as one clicks OK Another app that uses ttyUSB0 (JNOS) also causes hang as soon as tty is attached so it isn't gtkterm. Expected results: See serial stream Additional info: Works fine with Prolific 2302 based converter (067b:2303) Works fine on Fedora 17 ARM on Beagle Works fine on Fedora 18 x86_64 Hangs on F18 -or- Pidora on Raspi
Coincidentially usbmon has no arm module and may break something on the Pi, but only if monitoring is enabled.
I'm fairly sure the upstream maintainers have said the USB ports on the Pi are horrible and have issues in the hardware. You might also be having power issues as well. I don't expect much in the way of fixes to be honest. Also, Fedora doesn't build or provide a kernel for the Pi. You'd probably need to discuss this with the Seneca people doing the remix.
Here's the G+ thread where people dump on Pi's USB HC: https://plus.google.com/u/0/111049168280159033135/posts/63CBdNN4r4Z
The RPi kernel is not the same kernel we use in Fedora so there's nothing we can actually do. Your best bet is to contract someone on #seneca. Make sure your power supply supplies enough power, a standard 500ma USB charger isn't enough for anything that draws power through the usb bus. I would likely try a usb psu from a tablet that will supply 2A.
Thanks for the input. After Josh's comments about power I retested with a known stiff supply and it made no difference. Meanwhile, I learned about the availability of an I2C device which will be much nicer anyway.