Return-path: Received: from mail-pd0-f180.google.com ([209.85.192.180]:59754 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753878AbaJXLaW convert rfc822-to-8bit (ORCPT ); Fri, 24 Oct 2014 07:30:22 -0400 Received: by mail-pd0-f180.google.com with SMTP id fp1so1312827pdb.11 for ; Fri, 24 Oct 2014 04:30:22 -0700 (PDT) Date: Fri, 24 Oct 2014 20:30:19 +0900 From: Okhwan Lee To: Michal Kazior Cc: linux-wireless , "=?utf-8?Q?ath10k=40lists.infradead.org?=" Message-ID: (sfid-20141024_133026_517873_67D15D72) In-Reply-To: References: Subject: Re: Change channel bandwidth without iw command MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-wireless-owner@vger.kernel.org List-ID:  Hi,  This linked images are the printed error messages when the kernel is in panic.  http://www.mwnl.snu.ac.kr/~ohlee/1.jpg http://www.mwnl.snu.ac.kr/~ohlee/2.jpg Thank you for your help. Okhwan -- Okhwan Lee Sent with Airmail 켜짐 2014년 10월 24일 에서 오후 4:49:23, Michal Kazior (michal.kazior@tieto.com(mailto:michal.kazior@tieto.com)) 작성됨: > On 23 October 2014 08:57, Okhwan Lee wrote: > > Hi, > > > > Thank you for your answer. > > > >> The panic printout would be most helpful. My best guess is this > >> crashes in ath10k_dbg() at the very beginning of ath10k_config_chan > >> because ar->chandef.chan is NULL. This is probably the case since you > >> use monitor_chandef which is probably "empty" at the point you invoke > >> your code. > > > > First, we confirm that ar->chandef.chan is not NULL. > > We find out the the error occurs when "wait_for_completion_timeout" is called. > > Ath10k is trying to stop vdev (monitor_dev) when change the channel setting. > > We have no idea about the details of function, but it make waiting > > time duration for previous event. > > We also test by replacing wait_for_completion_timeout to > > wait_for_completion (i.e., it use maximum timeout value) > > But the kernel panic is still there. > > > > However, it is not easy to printout the messages when the panic is occurred, > > because the system stop (similar to bluescreen in widnows?). > > After reboot the system, the log messagess from panic is not recored > > in kernel log messages (/var/log/syslog, dmesg, kernel_llog) . > > Can you at least do a photo of the panic, post it to an image hosting > site and link it, please? > > > Michał