2014-09-23 21:17:47

by Larry Finger

[permalink] [raw]
Subject: Question about channel width

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