Ubuntu
net-tools package

killing slattach with bytes in buffer freezes system

Bug #396930 reported by Ambricka on 2009-07-08

This bug report is a duplicate of: Bug #376128: ftdi_sio doesnt work propertly. Edit Remove

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	net-tools (Ubuntu)	New	Undecided	Unassigned

Bug Description

Binary package hint: net-tools

Distributor ID: Ubuntu
Description: Ubuntu 9.04
Release: 9.04
Codename: jaunty
Linux bunke 2.6.28-13-generic #45-Ubuntu SMP Tue Jun 30 22:12:12 UTC 2009 x86_64 GNU/Linux

to reproduce:
slattach -p slip /dev/ttyUSB0
ifconfig sl0 ...
ping or anything to the other side
make sure the other side hasn't received the data
kill slattach process
experience a frozen system

it could also be a problem of ftdi-sio, but I haven't managed to freeze the system with that driver any other way.

Revision history for this message

Jim Paris (jim-jtan) wrote on 2009-07-22:

This is probably the same as #376128, which has been fixed in newer kernels (anything not 2.6.28).

Revision history for this message

Ambricka (petter-ambricka) wrote on 2009-07-23:

Not so sure about that. (Ok, I have to read it more carefully later...)
I have no problem using my (yes) ftdi /dev/ttyUSB?, the only real problem I've encountered with it is this. slip works, (to my commodore 64) and everything else works.
But if I forget to drain the buffer (on the other side) before I kill slattach my linux system freeze.
If you are sure it's related to #376128 I give up, else we have some other problem.

Revision history for this message

Jim Paris (jim-jtan) wrote on 2009-07-24:

Hi Ambricka,
All 2.6.28 kernels have a problem where FTDI devices will cause problems if the device is closed when the FTDI still has data in its buffer. I'd suggest trying a new kernel -- it's easy. Just download and install:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.30.2/linux-image-2.6.30-02063002-generic_2.6.30-02063002_amd64.deb
Hope it helps!