Return-path: Received: from mail-forward2.uio.no ([129.240.10.71]:41928 "EHLO mail-forward2.uio.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754214Ab2F1Pmf (ORCPT ); Thu, 28 Jun 2012 11:42:35 -0400 Received: from exim by mail-out2.uio.no with local-bsmtp (Exim 4.75) (envelope-from ) id 1SkGra-0000pt-5s for linux-wireless@vger.kernel.org; Thu, 28 Jun 2012 17:42:34 +0200 Message-ID: <4FEC7B66.5060409@cern.ch> (sfid-20120628_174238_703886_D8BCB6B0) Date: Thu, 28 Jun 2012 17:42:30 +0200 From: Jon Wikne MIME-Version: 1.0 To: Mohammed Shafi CC: linux-wireless@vger.kernel.org Subject: Re: Mysterious hangs - cfg80211 - ath9k References: <4FE03291.5030202@cern.ch> <4FE0CA6C.3080002@cern.ch> <4FEC6447.7010007@cern.ch> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 06/28/2012 04:22 PM, Mohammed Shafi wrote: > Hi, > > On Thu, Jun 28, 2012 at 7:33 PM, Jon Wikne wrote: >> On 06/19/2012 08:52 PM, Jon Wikne wrote: >>> >>> On 06/19/2012 11:39 AM, Mohammed Shafi wrote: >>>> >>>> On Tue, Jun 19, 2012 at 1:34 PM, Jon Wikne wrote: >>>>> >>>>> 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.) >>>> >>>> >>>> please quickly try >>>> >>>> http://linuxwireless.org/en/users/Download#Where_to_download_bleeding_edge >>> >>> >>> I tried to install compat-wireless-2012-05-10. It worked for 4? hours, >>> then same problem. >>> >>> Maybe there is something wrong with my understanding here, but I do not >>> see why the "cfg80211: Calling CRDA to update world regulatory domain" >>> should occur hours after the connection has been established, and what >>> triggers it, apparently at random.... >>> >>>> or the latest wireless testing tree >>>> >>>> http://linuxwireless.org/en/developers/Documentation/git-guide#Cloning_latest_wireless-testing >>> >>> >>> Is there a reason to believe it could make a difference if I try >>> this too? >> >> >> Now I downloaded this (more than 1GB), just to realize that it is a >> complete kernel tree for kernel 3.5.0-rc3. I don't really feel ready >> for an experimental upgrade from 2.6.39.4 to that right now.... >> >> With basis in compat-wireless-2012-05-10 I tried to comment out the >> call to call_crda in net/wireless/reg.c and return -EALREADY in line >> 1483, just to see if that circumvented the problem. It did not. The >> damage (whatever that might be) already seems to be done _before_ the >> call_crda is made in reg.c. >> >> I am a bit at a loss as to how to proceed. There are several things >> i do not understand. >> >> 1) The call to update CRDA (even with my crude, experimental, dummy >> return) seems to cause no trouble when it is done the first time >> the line comes up. Could someone please explain to me what causes >> the subsequent calls at highly irregular intervals, and why that >> seems to be necessary or desirable? >> >> 2) Is this a known problem that is being worked on (in which case I >> will just shut up and wait), or am I the first to report it? >> >> Thanks in advance for any further info or suggestions. > > please provide the complete log. There is nothing relevant in the regular logs apart from lines like these: Jun 20 17:11:09 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain Jun 20 17:11:09 redcat kernel: ath9k 0000:03:00.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18 when the WLAN comes up normally, and and an additional line like this: Jun 20 17:42:32 redcat kernel: cfg80211: Calling CRDA to update world regulatory domain when it fails / hangs at some unpredictable point in time later. > you can also enable ath9k debugging. > sudo modprobe -v ath9k debug=0x601 > http://linuxwireless.org/en/users/Drivers/ath9k/debug > so you need to bring the interface up/down to make it working right ? OK, done. I don't know when the error might reappear, but I will copy the /sys/kernel/debug/ieee80211/phy0/ tree and put on some server for forensics when it does. There is a lot of info there which I do not know how to interpret. Regards, -- Jon