From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-forward2.uio.no ([129.240.10.71]:48936 "EHLO mail-forward2.uio.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753930Ab2FSIgQ (ORCPT ); Tue, 19 Jun 2012 04:36:16 -0400 Received: from exim by mail-out2.uio.no with local-bsmtp (Exim 4.75) (envelope-from ) id 1SgtQP-0002xL-HF for linux-wireless@vger.kernel.org; Tue, 19 Jun 2012 10:04:33 +0200 Received: from mail-mx3.uio.no ([129.240.10.44]) by mail-out2.uio.no with esmtp (Exim 4.75) (envelope-from ) id 1SgtQP-0002xI-GP for linux-wireless@vger.kernel.org; Tue, 19 Jun 2012 10:04:33 +0200 Received: from cheetah.uio.no ([129.240.84.23]) by mail-mx3.uio.no with esmtp (Exim 4.76) (envelope-from ) id 1SgtQO-0005VF-WF for linux-wireless@vger.kernel.org; Tue, 19 Jun 2012 10:04:33 +0200 Message-ID: <4FE03291.5030202@cern.ch> (sfid-20120619_103623_225076_427B32F6) Date: Tue, 19 Jun 2012 10:04:33 +0200 From: Jon Wikne MIME-Version: 1.0 To: linux-wireless@vger.kernel.org CC: wikne@cheetah.uio.no Subject: Mysterious hangs - cfg80211 - ath9k Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi List, I am experiencing a puzzling problem with WLAN on a Toshiba Qosmio F750 laptop, running CERN SLC 5.8 (mostly identical to RHEL 5.8), but with kernel 2.6.39.4. (The kernel that came with the distro did not work properly with WLAN on this machine at all.) What happens is that the WLAN comes up flawlessly, and works well until it suddenly hangs. This happens when (or seconds after) I see an entry like the following in the log: Jun 18 19:04:42 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain I do not understand why cfg80211 does this long after the connection has been established. If I understand correctly, this "regulatory domain" business only makes sense when the WLAN interface is started. Subsequent DHCP requests are issued, but never answered: Jun 18 19:23:38 redcat dhclient: DHCPREQUEST on wlan0 to 137.138.16.6 port 67 (xid=0x63998557) Jun 18 19:24:16 redcat last message repeated 3 times Jun 18 19:25:30 redcat last message repeated 6 times ..... Jun 18 19:50:10 redcat dhclient: DHCPREQUEST on wlan0 to 255.255.255.255 port 67 (xid=0x63998557) Jun 18 19:50:55 redcat last message repeated 3 times ..... Jun 18 19:58:41 redcat dhclient: No DHCPOFFERS received. I interpret this as something has (effectively) been turned off, but that the drivers do not realize this. Restarting WLAN when the problem has occurred is simple: root@redcat 97 # /sbin/ifdown wlan0 root@redcat 98 # /sbin/ifup wlan0 What puzzles me even more is that cfg80211 seems to be activated and mess up things at highly irregular intervals, ranging from a few minutes to many hours: root@redcat 105 # tail -2000l /var/log/messages | grep cfg80211 Jun 17 20:28:51 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 17 23:09:37 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 17 23:36:01 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 18 09:27:59 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 18 11:57:48 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 18 18:42:00 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 18 18:46:49 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 18 19:04:42 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 18 22:40:42 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain At the time of writing this (Tue 19 Jun 2012 09:27:54 CEST) the WLAN has not stopped since the last entry in the above. What on earth is governing the timing in this? Some relevant info on the laptop: root@redcat 108 # lspci ..... 03:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01) ..... root@redcat 109 # lsmod Module Size Used by ..... ath9k 89934 0 mac80211 160999 1 ath9k ath9k_common 3051 1 ath9k ..... ath9k_hw 291258 2 ath9k,ath9k_common ath 15289 2 ath9k,ath9k_hw ..... cfg80211 141299 3 ath9k,mac80211,ath Any ideas will be greatly appreciated. I will be happy to test patches. Please CC me at jon.wikne@cern.ch since I am not on the list. Regards, -- Jon Wikne