Wireless Scan does not complete when QCA9880 is set to DFS channel

Software
1

When set to channel 36, scan completes and sees both 2.4G and 5G stations.

TurrisOS 4.0.5 ab9d1bf on Omnia.

I am using ath10k-firmware-qca988x-ct-htt and kmod-ath10k-ct because of this issue:

However, wireless scan had the same issue with the non -ct firmare/driver too.

I am starting to doubt the wisdom of upgrading to 4.x. Any ideas how could I debug this?

2

Just a sidenote: I had the same issue on Turris OS 3.X, but as I am on Turris OS 4 now, too, I can‘t check…

So this shouldn’t be related to Turris OS 4.

But I don‘t know how to debug this…

3

I cannot refute that, don’t remember trying DFS channels on 3.x. Scan might as well have been working like this before.

4 
root@MarPort:~# iwlist wlan0 scanning
wlan0     Interface doesn't support scanning : Resource busy

Seems like it‘s not a LuCI bug, but directly related to wifi interface. Maybe scanning is blocked because the wifi card needs to scan constantly for interfering radio signals on DFS channels…

5

Indeed, iw wlan0 scan too returns resource busy. Radar is monitored by looking for phy errors or specific pulse patterns, but on the currently occupied channel. If radar is detected it backs off immediately and switches channel. Before occupying any DFS channel, it takes around 1 min to passively monitor it for radar presence. There should be no continuous monitoring of ALL channels all the time.

6

+1 using TurrisOS 5.0.0.

Did switching to ath10k-firmware-qca988x-ct-htt and kmod-ath10k-ct make it work again?

7

Driver/firmware -ct do not make scan work. The other issue I was referring to, the driver crashing, seems to be solved in the limited testing I did.