Bugzilla – Bug 1579
iwl3945 does not detect all AP's and is too slow for NetworkManager
Last modified: 2008-06-16 19:43:48
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Hello, What I can say for sure: o Configuring the device manually (ifconfig, iwlist, iwconfig) everything works o "iwlist wlan0 scan" takes more time with iwl3945 than with ipw3945 o "iwlist wlan0 scan" returns sometimes no results, or just a few - (2 or 3) of 7 AP's are detected (ipw3945 detects all 7 of them) Issues with NetworkManager ---------------------------- So these are the facts. I also use NetworkManager. Booting the systems and logging in, I just get connected to the right network. But doing a reconnect via NetworkManager I get the following: o "Activation (wlan0/wireless): association took too long (>40s), asking for new key." o Several times I got something like: "scan took to long, get a better card" or something like this from NM, but now I can't reproduce this anymore. Used software versions -------------------------- Kernel: 2.6.23-ARCH (Distri: current Arch Linux) iwl3945: 1.2.23ds (latest snapshot, from 25 Dec. 2007) iwlwifi-3945-ucode: 2.14.1.5-2 mac80211: default kernel version (2.6.23-ARCH)
Here I went across a similar case. My test environment is FC kernel 2.6.23, mac80211-10.0.4, iwlwifi-1.2.25ds, 3945-ucode-2.14.1.5. sometimes I run"iwlist wlan0 scan", it showed: wlan0 No scan results And such thing occured with big probability. attchment scan.log is a dmesg log file with debug=0x43fff.
Created an attachment (id=1361) [details] scan.log
When iwlist returns "wlan0 No scan results" - can you confirm that you are running the command as root?
(In reply to comment #3) > When iwlist returns "wlan0 No scan results" - can you confirm that you are > running the command as root? yes, I'm sure I'm the root user, and sometime it did show scan results, but intermittently it scanned for nothing.
*** Bug 1586 has been marked as a duplicate of this bug. ***
Good morning, I'm so sorry, but I find out my iwl3945 is working well. The problem likely was with lower sensitivity than with ipw3945. I'm able to search and connect to the network now. I'm using (root rights -> sudo) for setting network, steps sudo ifconfig wlan0 up, sudo iwlist scan..... I consider my request as solved (bug 1586) Thanks a lot Petr Bartel
I Have a simmilar case as I have posted in the mailing list: Hi I have two laptops, one with ipw2200 the other with iwl3945 both running ubuntu hardy If I sit them together the ipw2200 can see some aps while the iwl3945 can not. Also if I use ipwraw and the airodump-ng its able to see all the aps that the iwl3945 was not able... I can confirm also the same behavior on no results after running: iwlst: mcanedo@xps-mac:~$ sudo iwlist wlan0 scan [sudo] password for mcanedo: wlan0 No scan results Please let me know if there is some information I might provide in order to help Regards, Miguel
One more thing: These no results from iwlist are at this same moment while I'm already connected via an associated ap, posting this reply.
Are any of the APs that do not show up during the scan perhaps hidden?
Created an attachment (id=1386) [details] screenshot
(In reply to comment #9) > Are any of the APs that do not show up during the scan perhaps hidden? > No they are not hidden. I have attached a screenshot. First try on iwlist has no results. Second try on iwlist return one app. The network-manager applet reports two apps. (I'm connected) At the same time the other laptop with the ipw2200 is seeing two additional aps. (a total of four)
I have updated the driver via the package: linux-backports-modules-hardy-generic in Ubuntu Hardy And it feel to work better Even the LED is working now.
Is this still an issue? It may be that the HW scanning does not wait long enough on each channel for an AP to respond. Depending on the band you are interested in, try to increase the values of IWL_ACTIVE_DWELL_TIME_24 or IWL_ACTIVE_DWELL_TIME_52 (found in iwl3945-base.c). Setting IWL_PLCP_QUIET_THRESH to zero may also help. For a reference, the mac80211 stack uses 30msec for active and 200msec for passive. Could you please try it out? Marking this as needsmoredata to find out of this is still an issue or to hear the results from the testing.
Resurrecting this since it doesn't work for me. I'm running Kubuntu 8.04 x64 with the 2.6.24-16-generic kernel and the linux-backports-modules-hardy package installed. zorael@sunspire:~$ modinfo iwl3945 filename: /lib/modules/2.6.24-16-generic/updates/wireless/iwlwifi/iwlwifi/compatible/iwl3945.ko license: GPL author: Copyright(c) 2003-2007 Intel Corporation version: 1.2.25 description: Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux srcversion: FDE2E62843DE3ED112A50C3 alias: pci:v00008086d00004227sv*sd*bc*sc*i* alias: pci:v00008086d00004222sv*sd*bc*sc*i* depends: led-class,iwlwifi_mac80211 vermagic: 2.6.24-16-generic SMP mod_unload (truncated) I've basically given up on KNetworkManager because it never works and always messes up routes, so I'm using ifconfig and iwconfig to connect. Even so, the card usually works early after boot, but if I disable it via the kill switch it often stops working completely. modprobing the module doesn't help, nor does toggling the kill switch on and off. I *know* the essid I'm trying to connect to is working (phone is connected next to the computer), and when I manage to connect I get about ~40% signal strength, yet even then sudo iwlist scan finds nothing. And yes, it does take exactly 10 seconds to scan, whereas with ipw3945 the scan was pretty instant. The router is broadcasting. zorael@sunspire:~$ iwconfig wlan0 wlan0 IEEE 802.11g ESSID:"lappskole" Nickname:"" Mode:Managed Frequency:2.412 GHz Access Point: Not-Associated Tx-Power=27 dBm Retry min limit:7 RTS thr:off Fragment thr=2346 B Power Management:off Link Quality:0 Signal level:0 Noise level:0 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 zorael@sunspire:~$ sudo iwlist wlan0 scan wlan0 No scan results (takes 10 seconds) At this point the interface is in its "broken" state. While it can connect to the AP in its working state, even then scanning ends up with no results 18 times out of 20; I've actually had it find it once. The module didn't work at all for me in Gutsy, at which point I followed the guide at http://linuxwireless.org/en/users/Download, which got it working again. I'm not using the interface currently so I thought I'd leave it broken to be of use for diagnosis. I haven't tried this now in Hardy. Any advice?
Creating /etc/modprobe.d/iwl3945 with the following contents makes it work, though still takes exactly 10 seconds to scan for networks. alias wlan0 iwl3945 options iwl3945 disable_hw_scan=1
Change status to "fixed" according to comment #15
Verified with latest snapshot. iwl3945 can detect most APs. And NetworkManager also works well on it, though sometimes it fails to connect with AP which has signal quality less than 50%.