Look ma, I found a kernel bug!

Oh great. I have experienced random hangups of my Laptop recently, and I had absolutely no clue what caused them, even after a reboot and looking into the logfiles. Today, after another hangup/crash I think I found the problem (but not the solution):

May 16 00:08:35 localhost kernel: NETDEV WATCHDOG: eth0: transmit timed out
May 16 00:08:35 localhost kernel: sky2 eth0: tx timeout
May 16 00:08:35 localhost kernel: x45 [sky2]
May 16 00:08:35 localhost kernel:  [pg0+943960755/1069376512] sky2_poll+0x469/0x548 [sky2]
May 16 00:08:35 localhost kernel:  [pg0+953407031/1069376512] nv_kern_isr+0x31/0x63 [nvidia]
May 16 00:08:35 localhost kernel:  [net_rx_action+82/199] net_rx_action+0x52/0xc7
May 16 00:08:35 localhost kernel:  [__do_softirq+52/125] __do_softirq+0x34/0x7d
May 16 00:08:35 localhost kernel:  [do_softirq+34/38] do_softirq+0x22/0x26
May 16 00:08:35 localhost kernel:  [irq_exit+41/52] irq_exit+0x29/0x34
May 16 00:44:32 localhost syslogd 1.4.1#17.2: restart.
May 16 00:44:32 localhost kernel: klogd 1.4.1#17.2, log source = /proc/kmsg started.

Note that I could do absolutely nothing on the laptop anymore, no moving the mouse, no typing on the keyboard, no switching from X11 into a text console, no CTRL+ALT+BACKSPACE to kill X11, no CTRL+ALT+DELETE to reboot, nothing.

I think sky2 (network driver) or the NVIDIA driver may be the culprit (or a combination of both). After some searching it seems other people have/had similar problems, but not quite the same...

I guess I'll have to file a bugreport somewhere...

Ad-hoc WLAN Network in the Subway

Some technologies have the ability to really amaze me. Last week I was sitting in a subway/metro train with Daniel Reutter, driving home from university.

We had the idea to try to run a wireless ad-hoc network. So we did. In just a few minutes Daniel configured his Powerbook (or iBook? I don't know for sure) for ad-hoc networking, and I did the same on my Debian-based shiny new Toshiba Satellite A80-117.

I added the following lines to my /etc/network/interfaces:

auto eth1
iface eth1 inet static
  wireless_mode ad-hoc
  wireless_essid foobar
  wireless_channel 11

Then I issued /etc/init.d/networking restart and that was it. We could ping each other, ssh between our boxes, exchange files, chat, play networked games, whatever.

Although this is probably nothing new for most of you, it was the first time I tried it, and I was really amazed at how painlessly it was to configure and even more that it Just Worked(tm) out of the box. We were travelling a few meters under the earth, no cell phone connections possible, and still could do any networking stuff we liked. Call me easy to impress, but somehow that's just plain amazing.

Syndicate content