Iwl3945 module loading problem (with workaround)

Question

I've been experiencing problems with my intel wireless card (iwl3945) not loading at boot time. The problem arose after a fresh install from a Chakra (kdemod) live CD after I got a new harddrive for my notebook. It worked fine from the live CD and immediately post-install but when I upgraded the system with "pacman -Syu" (the kernel was upgraded as part of this) the card no longer loaded during boot (i.e. wlan0 would not show up under "ifconfig -a").
I checked some threads on the iwl3945 (e.g. http://bbs.archlinux.org/viewtopic.php? … 18#p638618 and http://bbs.archlinux.org/viewtopic.php?id=73876) but couldn't find quite the same behaviour so decided to start a new thread.
It's also similar to this thread (http://bbs.archlinux.org/viewtopic.php?id=82357), but this is not for the iwl3945.
The following is a log of the problem:
$ ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:15:C5:46:C6:6A
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:24 errors:0 dropped:0 overruns:0 frame:0
TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1240 (1.2 Kb) TX bytes:1240 (1.2 Kb)
$ ifconfig wlan0 up
wlan0: unknown interface: No such device
$ lsmod | grep iwl
iwl3945 89020 0
iwlcore 107100 1 iwl3945
mac80211 155532 2 iwl3945,iwlcore
led_class 4000 3 sdhci,iwl3945,iwlcore
cfg80211 90428 3 iwl3945,iwlcore,mac80211
$ dmesg | grep iwl
iwl3945: Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux, 1.2.26ks
iwl3945: Copyright(c) 2003-2009 Intel Corporation
iwl3945 0000:0c:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
iwl3945 0000:0c:00.0: setting latency timer to 64
iwl3945 0000:0c:00.0: Tunable channels: 13 802.11bg, 23 802.11a channels
iwl3945 0000:0c:00.0: Detected Intel Wireless WiFi Link 3945ABG
iwl3945 0000:0c:00.0: irq 28 for MSI/MSI-X
iwl3945 0000:0c:00.0: Failed to register hw (error -2)
iwl3945 0000:0c:00.0: PCI INT A disabled
iwl3945: probe of 0000:0c:00.0 failed with error -2
Here is my rc.conf
# /etc/rc.conf - Main Configuration for Arch Linux
# LOCALIZATION
# LOCALE: available languages can be listed with the 'locale -a' command
# HARDWARECLOCK: set to "UTC" or "localtime", any other value will result
# in the hardware clock being left untouched (useful for virtualization)
# TIMEZONE: timezones are found in /usr/share/zoneinfo
# KEYMAP: keymaps are found in /usr/share/kbd/keymaps
# CONSOLEFONT: found in /usr/share/kbd/consolefonts (only needed for non-US)
# CONSOLEMAP: found in /usr/share/kbd/consoletrans
# USECOLOR: use ANSI color sequences in startup messages
LOCALE="en_GB.utf8"
HARDWARECLOCK="localtime"
TIMEZONE="Europe/Dublin"
KEYMAP="uk"
CONSOLEFONT=
CONSOLEMAP=
USECOLOR="yes"
# HARDWARE
# MOD_AUTOLOAD: Allow autoloading of modules at boot and when needed
# MOD_BLACKLIST: Prevent udev from loading these modules
# MODULES: Modules to load at boot-up. Prefix with a ! to blacklist.
# NOTE: Use of 'MOD_BLACKLIST' is deprecated. Please use ! in the MODULES array.
MOD_AUTOLOAD="yes"
#MOD_BLACKLIST=() #deprecated
MODULES=(b44 mii !ipw3945 iwlcore pcspkr snd-mixer-oss snd-pcm-oss snd-hwdep snd-page-alloc snd-pcm snd-timer snd snd-hda-codec snd-hda-intel soundcore)
# Scan for LVM volume groups at startup, required if you use LVM
USELVM="no"
# NETWORKING
# HOSTNAME: Hostname of machine. Should also be put in /etc/hosts
HOSTNAME="alex-xps"
# Use 'ifconfig -a' or 'ls /sys/class/net/' to see all available interfaces.
# Interfaces to start at boot-up (in this order)
# Declare each interface then list in INTERFACES
# - prefix an entry in INTERFACES with a ! to disable it
# - no hyphens in your interface names - Bash doesn't like it
eth0="dhcp"
# Wireless: See network profiles below
wlan0="dhcp"
#Static IP example
#eth0="eth0 134.226.144.162 netmask 255.255.0.0 broadcast 134.226.255.255"
INTERFACES=(!eth0 !eth1 !wlan0)
# Routes to start at boot-up (in this order)
# Declare each route then list in ROUTES
# - prefix an entry in ROUTES with a ! to disable it
gateway="default gw 192.168.0.1"
ROUTES=(!gateway)
# Enable these network profiles at boot-up. These are only useful
# if you happen to need multiple network configurations (ie, laptop users)
# - set to 'menu' to present a menu during boot-up (dialog package required)
# - prefix an entry with a ! to disable it
# Network profiles are found in /etc/network.d
# This now requires the netcfg package
#NETWORKS=(main)
# DAEMONS
# Daemons to start at boot-up (in this order)
# - prefix a daemon with a ! to disable it
# - prefix a daemon with a @ to start it up in the background
DAEMONS=(syslog-ng hal !network wicd !networkmanager avahi-daemon avahi-dnsconfd alsa cdemud kdm)
I read somewhere that there was an issue with kill switches and that rfkill may help so I installed it from AUR. However, there didn't seem to be any block:
$ rfkill list
1: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
2: dell-wifi: Wireless LAN
Soft blocked: no
Hard blocked: no
3: dell-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
I also tried creating a modprobe.conf file as suggested in some quarters (/etc/modprobe.d/iwl3945.conf):
alias wlan0 iwl3945
options iwl3945 disable_hw_scan=1
Sadly still no luck on a reboot.
After much pulling of hair the following workaround finally did it for me. Basically even though the module doesn't load during boot I can remove it and then modprobe it manually and it then works so that I can bring up the interface:
# rmmod iwl3945
# modprobe iw3945
# ifconfig wlan0 up
# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:15:C5:46:C6:6A
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:24 errors:0 dropped:0 overruns:0 frame:0
TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1240 (1.2 Kb) TX bytes:1240 (1.2 Kb)
wlan0 Link encap:Ethernet HWaddr 00:18:DE:1E:7B:46
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
wmaster0 Link encap:UNSPEC HWaddr 00-18-DE-1E-7B-46-00-00-00-00-00-00-00-00-00-00
UP RUNNING MTU:0 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
I can then use wicd to connect to my router at home (networkmanager doesn't seem to work for me with the same settings).
Hopefully this may be of some use to someone with the same issue and to any kernel gurus that may be scanning this section of the forum.

Answer 1

I tinkered with the rfkill module as suggested.
First checked what the default behaviour was
$ lsmod | grep rfkill
rfkill 19728 3 bluetooth,dell_laptop,cfg80211
Then blacklisted rfkill in rc.conf using "!rfkill" in the modules line
$ lsmod | grep rfkill
rfkill 19728 1 cfg80211
Unfortunately I still had to manually remove and reload iwl3945 as before.
I tried inserting the options in modprobe.conf suggested by you in your other post
# /etc/modprobe.d/modprobe.conf (for v2.6 kernels)
options bluetooth rfkill=0
options dell_laptop rfkill=0
After a reboot still no wireless activity and checking rfkill module gives same as for blacklisting in rc.conf, i.e. ...
$ lsmod | grep rfkill
rfkill 19728 1 cfg80211
So still manually un/reloading as before. At least the workaround is not too labour intensive.