em(4) on thinkpad t60

[Michal Belczyk <belczyk@xxxxxxxxxxxxx>]

Hello,

after replacing my workstation (R40e) with T60 I noticed the following
problems regarding em(4) device:


1. If {em0, pcib2} interrupts are set to X in the bios and {pcib1, pci1(ATI),
uhci0, cbb0} interrupts are set to Y, then I get livelock from interrupt Y
after bringing em0 up.  When they're set to the same value it works fine.


2. The em0 interface can't be configured unless the cable is plugged in
(probably a known issue).


3. Network connections work very slowly unless polling(4) is enabled for em0:

  ping from another machine in my home lan (100Mbps):
  envy# ping -c 5 grazer
  PING grazer.bsd.krakow.pl (10.0.0.5): 56 data bytes
  64 bytes from 10.0.0.5: icmp_seq=0 ttl=64 time=818.905 ms
  64 bytes from 10.0.0.5: icmp_seq=1 ttl=64 time=693.269 ms
  64 bytes from 10.0.0.5: icmp_seq=2 ttl=64 time=793.187 ms
  64 bytes from 10.0.0.5: icmp_seq=3 ttl=64 time=783.224 ms
  64 bytes from 10.0.0.5: icmp_seq=4 ttl=64 time=773.265 ms
  --- grazer.bsd.krakow.pl ping statistics ---
  5 packets transmitted, 5 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 693.269/772.370/818.905/42.366 ms

  other way round is better:
  grazer# ping -c 5 envy
  PING envy.bsd.krakow.pl (10.0.0.100): 56 data bytes
  64 bytes from 10.0.0.100: icmp_seq=0 ttl=64 time=0.535 ms
  64 bytes from 10.0.0.100: icmp_seq=1 ttl=64 time=0.490 ms
  64 bytes from 10.0.0.100: icmp_seq=2 ttl=64 time=0.459 ms
  64 bytes from 10.0.0.100: icmp_seq=3 ttl=64 time=0.426 ms
  64 bytes from 10.0.0.100: icmp_seq=4 ttl=64 time=0.397 ms
  --- envy.bsd.krakow.pl ping statistics ---
  5 packets transmitted, 5 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 0.397/0.461/0.535/0.048 ms

  With polling enabled I get:
  envy# ping -c 5 grazer
  PING grazer.bsd.krakow.pl (10.0.0.5): 56 data bytes
  64 bytes from 10.0.0.5: icmp_seq=0 ttl=64 time=2.030 ms
  64 bytes from 10.0.0.5: icmp_seq=1 ttl=64 time=7.755 ms
  64 bytes from 10.0.0.5: icmp_seq=2 ttl=64 time=7.914 ms
  64 bytes from 10.0.0.5: icmp_seq=3 ttl=64 time=8.072 ms
  64 bytes from 10.0.0.5: icmp_seq=4 ttl=64 time=8.227 ms
  --- grazer.bsd.krakow.pl ping statistics ---
  5 packets transmitted, 5 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 2.030/6.800/8.227/2.390 ms

  and the other way round:
  grazer# ping -c 5 envy
  PING envy.bsd.krakow.pl (10.0.0.100): 56 data bytes
  64 bytes from 10.0.0.100: icmp_seq=0 ttl=64 time=0.233 ms
  64 bytes from 10.0.0.100: icmp_seq=1 ttl=64 time=0.398 ms
  64 bytes from 10.0.0.100: icmp_seq=2 ttl=64 time=0.501 ms
  64 bytes from 10.0.0.100: icmp_seq=3 ttl=64 time=0.620 ms
  64 bytes from 10.0.0.100: icmp_seq=4 ttl=64 time=0.233 ms
  --- envy.bsd.krakow.pl ping statistics ---
  5 packets transmitted, 5 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 0.233/0.397/0.620/0.151 ms

Tested on both UP and SMP kernels (on SMP+APIC_IO em0 doesn't work and reports
watchdog timeouts).  My dmesg and kernel config are at
http://www.bsd.krakow.pl/grazer/
If you need more information I'm ready to help.


4. Setting

  kern.polling.enable=1 in /etc/sysctl.conf and
  ifconfig_em0="inet ... polling" in /etc/rc.conf

doesn't seem to have any effect after reboot and I have to manually do that
via "ifconfig em0 polling".


Now I'm going to test the intel wireless device :-)
TIA

-- 
Michal Belczyk