Thanks for the kernel bugzilla link, Dik, its power-save saving suspicion seems valid, at least now I had a full day of uptime without this wifi failure.
So, for anyone else who also wants to give it a try: 1. If you are using NetworkManager, then check '/etc/NetworkManager/conf.d/default-wifi-powersave-on.conf', and try setting 'wifi.powersave = 0' 2. If you aren't using NetworkManager, then you may add an udev rule for turning it off: Add this to '/etc/udev/rules.d/90-iwl3945-quirk.rules': # disable power saving, as per https://bugzilla.kernel.org/show_bug.cgi?id=93041 ACTION=="add", SUBSYSTEM=="net", ENV{DEVTYPE}=="wlan", ENV{ID_NET_DRIVER}=="iwl3945", RUN+="/sbin/iw dev %E{INTERFACE} set power_save off" NOTE: the '90-...' is important, as it must be evaluated after '80-drivers.rules' (I think). 3. You may set it manually via 'iw dev <iface> set power_save off', but it will last only until something overrides it, or until reboot. I collected some dmesg stack traces, this was the most relevant one (the rest came from generic ieee80211 code). [ 7729.780167] ------------[ cut here ]------------ [ 7729.780189] WARNING: CPU: 1 PID: 4563 at /build/linux-CQR1pk/linux-4.10.0/drivers/net/wireless/intel/iwlegacy/common.c:3178 il_enqueue_hcmd+0x35c/0x3d0 [iwlegacy] [ 7729.780191] Modules linked in: uas usb_storage ccm pcmcia coretemp kvm_intel kvm input_leds joydev arc4 irqbypass iwl3945 iwlegacy serio_raw mac80211 yenta_socket snd_hda_codec_conexant snd_hda_codec_generic pcmcia_rsrc lpc_ich pcmcia_core snd_hda_intel cfg80211 snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd soundcore shpchp toshiba_acpi sparse_keymap industrialio wmi mac_hid parport_pc ppdev lp parport ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic i915 8139too usbhid i2c_algo_bit psmouse drm_kms_helper syscopyarea 8139cp sysfillrect sysimgblt pata_acpi fb_sys_fops mii drm hid fjes video [ 7729.780260] CPU: 1 PID: 4563 Comm: kworker/u4:1 Tainted: G W 4.10.0-19-generic #21-Ubuntu [ 7729.780261] Hardware name: TOSHIBA SATELLITE L100/SATELLITE L100, BIOS V3.00 12/25/2008 [ 7729.780307] Workqueue: phy0 ieee80211_scan_work [mac80211] [ 7729.780309] Call Trace: [ 7729.780318] dump_stack+0x58/0x73 [ 7729.780321] __warn+0xea/0x110 [ 7729.780330] ? il_enqueue_hcmd+0x35c/0x3d0 [iwlegacy] [ 7729.780332] warn_slowpath_null+0x2a/0x30 [ 7729.780340] il_enqueue_hcmd+0x35c/0x3d0 [iwlegacy] [ 7729.780344] ? default_send_IPI_single+0x2c/0x30 [ 7729.780347] ? native_smp_send_reschedule+0x1f/0x40 [ 7729.780354] il_send_cmd_sync+0x40/0x340 [iwlegacy] [ 7729.780360] il3945_request_scan+0x3e6/0x5a0 [iwl3945] [ 7729.780368] il_mac_hw_scan+0x108/0x180 [iwlegacy] [ 7729.780400] __ieee80211_start_scan+0x22d/0x6a0 [mac80211] [ 7729.780433] ieee80211_scan_work+0x3db/0x4b0 [mac80211] [ 7729.780437] process_one_work+0x1b8/0x420 [ 7729.780440] worker_thread+0x37/0x4c0 [ 7729.780442] ? process_one_work+0x420/0x420 [ 7729.780445] kthread+0xd5/0x100 [ 7729.780447] ? process_one_work+0x420/0x420 [ 7729.780449] ? kthread_create_on_node+0x30/0x30 [ 7729.780453] ret_from_fork+0x21/0x2c [ 7729.780456] ---[ end trace 2fddf3f499f47c42 ]--- -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1408963 Title: [Xbuntu 14.04, 14.10 and 15.04] Network manager stops working: iwl3945 0000:03:00.0: BSM uCode verification failed at addr ...; wlan0: deauthenticating from... by local choice (Reason: 3=DEAUTH_LEAVING), Status in network-manager package in Ubuntu: Confirmed Bug description: From time to time, the system loses all wireles networks and kubuntu network manager applet goes blank - not even one network is shown. All wifi connections are broken. Rebooting fixes the issue, switching to WICD on-the-fly enables to continue browsing without rebooting, so it seems to be no hardware issue or iwl3945 issue. What to expect: stable connections and flawless network managing. What happens: so above. Further informations about the system, the network configuration, the package version can be found in the attachment, also parts of rsyslog and dmesg. Interesting, according to some helpers, are the following lines: dmesg: wlan0: deauthenticating from 02:26:4d:ac:8f:45 by local choice (Reason: 3=DEAUTH_LEAVING) lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.10 Release: 14.10 Codename: utopic apt-cache policy network-manager network-manager: Installiert: 0.9.8.8-0ubuntu28 Installationskandidat: 0.9.8.8-0ubuntu28 Versionstabelle: *** 0.9.8.8-0ubuntu28 0 500 http://de.archive.ubuntu.com/ubuntu/ utopic/main amd64 Packages 100 /var/lib/dpkg/status To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1408963/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
