AR6003 5.2GHz AP on channel 38

[Rostyslav Khudolii]

Hi all,

I'm trying to understand which primary channels are actually supported
by ath6kl + AR6003 and it's firmware.

It seems that I can start an AP using hostapd/wpa_supplicant on
channel 38 with no error from the cfg80211 layer, but the AR6003 FW
will send me "unknown error" over WMI, once
ath6kl_wmi_ap_profile_commit was executed.

As far as I know, AR6003 (according to the specs) supports both
802.11a and 802.11an modes and the difference between those to, when
it comes to operating frequencies, is actually a set of 38/42/46
channels, which are supported as primary by 802.11a and are not by
802.11n.

I looked into the latest ath10 driver and the channels mentioned above
aren't present there at all.

Also in ath6kl/main.c:416
if (ar->last_ch != channel)
/* we actually don't know the phymode, default to HT20 */
ath6kl_cfg80211_ch_switch_notify(vif, channel, WMI_11G_HT20);

we default to HT20, meaning that it's impossible to use 802.11a -
specific functionality?

So, my question is: would it be feasible to just remove those channels
from the supported list and forget about 802.11a like it's done in
ath10?
If no - how do I enable 802.11a then?

Any feedback would be much appreciated!