Ath10k DFS - where to put hostapd defines?

Installing and Using OpenWrt
1

Hi all,

I'm setting up mesh networking with ath10k. Everything works but I can't use DFS channels. I have set my /etc/config/wireless to switch the phy0 wireless device to 'DE' but according to iw that doesn't actually change the regulatory domain (longer outputs of commands and device config at the end of this post). This email suggests that ath10k can do FCC regulations and way down on this page it suggests I could use hostapd to force DFS zones / usage.

I've searched around and can't find what to install / what config files to use to push those hostapd commands for DFS regions into my router. The wireless doc page says to look for "hostapd-phy0.conf" but I cannot find any hostapd files on my system. What am I missing?

Any help would be greatly appreciated!

Router information: Archer C7 V2 using QCA988x firmware
/etc/config/wireless for 5GHz device:

config wifi-device 'radio0'
option type 'mac80211'
option channel '52'
option hwmode '11a'
option path 'pci0000:01/0000:01:00.0'
option htmode 'VHT80'
option country 'FR'
option disabled '0'
option log_level '3'

output of "iw reg get":

global
country FR: DFS-ETSI
(2402 - 2482 @ 40), (N/A, 20), (N/A)
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
(5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS
(57000 - 66000 @ 2160), (N/A, 40), (N/A)

phy#1
country US: DFS-FCC
(2402 - 2472 @ 40), (N/A, 30), (N/A)
(5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
(5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
(5735 - 5835 @ 80), (N/A, 30), (N/A)
(57240 - 63720 @ 2160), (N/A, 40), (N/A)

phy#0
country US: DFS-FCC
(2402 - 2472 @ 40), (N/A, 30), (N/A)
(5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
(5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
(5735 - 5835 @ 80), (N/A, 30), (N/A)
(57240 - 63720 @ 2160), (N/A, 40), (N/A)

Thanks,
Zach

2

I have the same issue with the same device. Kernel log show on boot that ath10k is set on region US. But not like the other wlan interface, its not changed while in the boot process into the chosen country.

PS: it might be necessary that one of us open a bug report the next days.

3

Wait, so you're suggesting this isn't a configuration option I'm missing, but a bug?

Did you try anything to work around this? Are there any hostapd defines that can help change the country code? I'm curious to know what avenues I shouldn't push down. Should I be sending an email out to the Ath10k folks?

Thanks,
Zach

4

The only result i had is messing up completely the ath10k interface. So probably open a report in that case is a reasonable solution, since it should work out of the box.

Its kinda important, since without the right country code, dfs cant work well, and it even let you choose forbiden channels and dBm depending on your country.

If you cant find the time, i probably will open a ticket on the weekend.

5

This is neither a configuration issue, nor a bug. DFS operation is only defined in Access Point mode. In a mesh network environment you cannot properly implement DFS as specified by IEEE 802.11 since the channel switch mechanism mandated by DFS relies on a central instance (the access point) to issue CSAs.

If all nodes of a mesh would simply hop to a random channel upon receipt of a radar pulse, the entire cell would quickly break down. There is currently no standard way to support DFS in mesh or IBSS mode at all and there is also no proprietary solution I am aware of.

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