Return-path: Received: from mail-wi0-f173.google.com ([209.85.212.173]:52397 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755567AbaJXHtX convert rfc822-to-8bit (ORCPT ); Fri, 24 Oct 2014 03:49:23 -0400 Received: by mail-wi0-f173.google.com with SMTP id ex7so551062wid.12 for ; Fri, 24 Oct 2014 00:49:22 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 24 Oct 2014 09:49:22 +0200 Message-ID: (sfid-20141024_094932_261301_6FE72E42) Subject: Re: Change channel bandwidth without iw command From: Michal Kazior To: Okhwan Lee Cc: "ath10k@lists.infradead.org" , linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: 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