Set the primary channel in HT40 mode

[Gaurang Ramesh Naik]

Hi All,

I have some difficulty in understanding how HT40, HT40- and HT40+
modes work. My objective is to set a particular 20 MHz channel as the
primary channel when channel bonding is enabled. From what I
understand, HT40- means secondary channel is below the primary, while
HT40+ means secondary channel is above the primary channel. I am
particularly dealing with channels 149, 153, 157 and 161.

When I set the channel to say 157, whether I use HT40+ or HT40-, the
primary channel is always set to channel 161. I am inferring this
because when I scan using iwlist scan, my SSID shows on Channel 161.
Does ath10k not set the primary and secondary channel in this manner?

If not, is there a mechanism by which I can explicitly mention which
channel must be primary, and which must be secondary? Also, how is the
primary channel decided for VHT80 mode?

Note: I am using OpenWrt in my AP. So I set the htmode as an option in
the /etc/config/wireless file.

Thanks,
Gaurang.