Hello.

On 15.10.2019 18:52, Oleksandr Natalenko wrote:

Thanks for the answer and the IRC discussion. As agreed I've applied
[1] and [2], and have just swapped the card to try it again. So far,
it works fine in 5 GHz band in 802.11ac mode as an AP.

I'll give it more load with my phone over evening, and we can discuss
what to do next (if needed) tomorrow again. Or feel free to drop me an
email today.

Thanks for your efforts.

[1]
https://github.com/LorenzoBianconi/wireless-drivers-next/commit/cf3436c42a297967235a9c9778620c585100529e.patch
[2]
https://github.com/LorenzoBianconi/wireless-drivers-next/commit/aad256eb62620f9646d39c1aa69234f50c89eed8.patch

As agreed, here are iperf3 results, AP to STA distance is 2 meters.

Client sends, TCP:

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  70.4 MBytes  59.0 Mbits/sec  3800             
sender
[  5]   0.00-10.03  sec  70.0 MBytes  58.6 Mbits/sec                  
receiver

Client receives, TCP:

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.06  sec   196 MBytes   163 Mbits/sec  3081             
sender
[  5]   0.00-10.01  sec   191 MBytes   160 Mbits/sec                  
receiver

Client sends, UDP, 128 streams:

[ ID] Interval           Transfer     Bitrate         Jitter    
Lost/Total Datagrams
[SUM]   0.00-10.00  sec   160 MBytes   134 Mbits/sec  0.000 ms  0/115894 
(0%)  sender
[SUM]   0.00-10.01  sec   160 MBytes   134 Mbits/sec  0.347 ms  0/115892 
(0%)  receiver

Client receives, UDP, 128 streams:

[ ID] Interval           Transfer     Bitrate         Jitter    
Lost/Total Datagrams
[SUM]   0.00-10.01  sec   119 MBytes  99.4 Mbits/sec  0.000 ms  0/85888 
(0%)  sender
[SUM]   0.00-10.00  sec   119 MBytes  99.5 Mbits/sec  0.877 ms  0/85888 
(0%)  receiver

Given the HW is not the most powerful, the key point here is that 
nothing crashed after doing these tests.

-- 
   Oleksandr Natalenko (post-factum)