Message-ID: <5421E379.4030504@lwfinger.net> (sfid-20140923_231751_901533_041897A5)
Date: Tue, 23 Sep 2014 16:17:45 -0500
From: Larry Finger <Larry.Finger@lwfinger.net>
MIME-Version: 1.0
To: "Berg, Johannes" <johannes.berg@intel.com>
CC: linux-wireless <linux-wireless@vger.kernel.org>
Subject: Question about channel width
Content-Type: text/plain; charset=utf-8; format=flowed
Sender: linux-wireless-owner@vger.kernel.org

Hi,

While investigating relatively poor performance on an 802.11n link, I noticed 
the following in the logs:

wlp2s0: capabilities/regulatory prevented using AP HT/VHT configuration, downgraded

On investigation, I found that the message comes from routine 
ieee80211_determine_chantype(). I am not sure why it gets to that part of the 
code; however, chandef->width and vht_chandef.width) are not equal The first is 
reasonable with a value of 1, but vht_chandef.width has an unreasonable value of 
9708.

Is there a quick explanation of why this is happening, and why vht_chandef is 
not being properly initialized? The AP supports 300 Mbps operations, and the NIC 
should handle 150.

Larry