Sistemas Operacionais -> Ubuntu -> Turning Wireless on Causes Laptop to Freeze on Ubuntu 11.04 Natty Narwhal?

Downgrading network-manager to a version from Jaunty didn't work. However, I've noticed that ifplugd package was not installed on my machine. After installation of this package hot plugging/unplugging of network cable became possible and didn't cause any issues.

It seems like ifplugd is not being installed with Karmic by default.

Excuse me, I'm wrong: ifplugd didn't help! The issue still exists!

This issue is generated also by desktop version of Ubuntu 9.10, not only UNR. It could be easily generated using live boot from USB flash without installing the Ubunto to hard drive:

1. Boot from live USB with Ethernet cable plugged;
2. Unplug Ethernet cable -- system crashes!

lspci | grep -i network
01:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g (rev 01)

See also #469313 - doesn't see wireless. Probably, same problem

It is definitely a bug and should be fixed... Please provide information about your hardware - maybe it helps developers to fix the bug.

Run:

lspci | grep -i net

In my case it returns:

01:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g (rev 01)
02:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8040 PCI-E Fast Ethernet Controller (rev ff)

Also, determine BIOS version by running:

sudo dmidecode

First lines of the output, in my case, are:

SMBIOS 2.4 present.
17 structures occupying 818 bytes.
Table at 0x000FC520.

Handle 0x0000, DMI type 0, 24 bytes
BIOS Information
Vendor: Hewlett-Packard
Version: 361A0 Ver. F.15
Release Date: 08/21/2009
Address: 0xF0000
Runtime Size: 64 kB
ROM Size: 1024 kB

----------------------------------------------------------------------------------------------------------------------------------

To cause the crash:

1. Start machine with cable plugged in but out of range of any configured wireless networks.
2. Log in and unplug the network cable. Machine hangs and must be powered down to restart.

To see network-manager not pick up the wired connection:

1. Start machine with cable unplugged and out of range of any configured wireless networks.
2. Log in and plug cable in. network-manager does not notice this and the wired network remains down.

Looks like this bug is fixed in karmic-proposed, there is also a workaround using "pci=use_crs" as a kernel parameter. Details here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/407824