WiFi 6 problem with Intel AX200 in Linux

[heistp]

I have an AX200 adapter in an HP ProBook 455 G7, with the latest BIOS 1.15, Linux kernel 6.6.16, and AX200 firmware version 77.ad46c98b.0, all recent as of this posting. It works fine when connected to a WiFi 4 AP, but with WiFi 6 (802.11ax), it is unusable unless power save mode is disabled.

Here's how an iperf3 looks with power save enabled (the default), right after association to a 5Ghz AP with 20 GHz channels (channel 40). It stops passing data almost immediately:

% iperf3 -R -t 30 -c xyz
Connecting to host xyz, port 5201
Reverse mode, remote host xyz is sending
[ 5] local 10.0.0.80 port 59492 connected to 10.0.0.251 port 5201
[ ID] Interval          Transfer    Bitrate
[ 5]  0.00-1.00  sec 8.00 MBytes 67.0 Mbits/sec                 
[ 5]  1.00-2.00  sec 4.12 MBytes 34.6 Mbits/sec                 
[ 5]  2.00-3.00  sec 0.00 Bytes 0.00 bits/sec                 
[ 5]  3.00-4.00  sec 0.00 Bytes 0.00 bits/sec                 
[ 5]  4.00-5.00  sec 0.00 Bytes 0.00 bits/sec                 
[ 5]  5.00-6.00  sec 0.00 Bytes 0.00 bits/sec                 
[ 5]  6.00-7.00  sec 0.00 Bytes 0.00 bits/sec                 
[ 5]  7.00-8.00  sec 0.00 Bytes 0.00 bits/sec                 
[ 5]  8.00-9.00  sec 0.00 Bytes 0.00 bits/sec                 
^C- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval          Transfer    Bitrate
[ 5]  0.00-9.04  sec 0.00 Bytes 0.00 bits/sec                 sender
[ 5]  0.00-9.04  sec 12.1 MBytes 11.3 Mbits/sec                 receiver
iperf3: interrupt - the client has terminated

It might start working later, only to quickly stop again. But, if I disable power save mode on the WiFi adapter, it works fine:

% sudo iw dev wlp2s0 set power_save off
% iperf3 -R -t 30 -c xyz
Connecting to host xyz, port 5201
Reverse mode, remote host xyz is sending
[ 5] local 10.0.0.80 port 51734 connected to 10.0.0.251 port 5201
[ ID] Interval          Transfer    Bitrate
[ 5]  0.00-1.00  sec 13.8 MBytes  115 Mbits/sec                 
[ 5]  1.00-2.00  sec 16.5 MBytes  138 Mbits/sec                 
[ 5]  2.00-3.00  sec 13.0 MBytes  109 Mbits/sec                 
[ 5]  3.00-4.00  sec 13.0 MBytes  109 Mbits/sec                 
[ 5]  4.00-5.00  sec 17.0 MBytes  143 Mbits/sec                 
[ 5]  5.00-6.00  sec 14.9 MBytes  125 Mbits/sec                 
[ 5]  6.00-7.00  sec 15.6 MBytes  131 Mbits/sec                 
[ 5]  7.00-8.00  sec 17.1 MBytes  144 Mbits/sec                 
[ 5]  8.00-9.00  sec 16.2 MBytes  136 Mbits/sec                 
[ 5]  9.00-10.00 sec 14.4 MBytes  121 Mbits/sec                 
[ 5] 10.00-11.00 sec 14.9 MBytes  125 Mbits/sec                 
^C[ 5] 11.00-11.59 sec 9.00 MBytes  129 Mbits/sec                 
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval          Transfer    Bitrate
[ 5]  0.00-11.59 sec 0.00 Bytes 0.00 bits/sec                 sender
[ 5]  0.00-11.59 sec  175 MBytes  127 Mbits/sec                 receiver
iperf3: interrupt - the client has terminated

I would rather not burn power and battery life needlessly though, and this is a real problem for people who don't figure this out, since it's the default.

Is there a fix for this so power save mode can work with WiFi 6?

[RamyerM_Intel]

Hello heistp, 

Thank you for posting in the communities. Kindly please send us your SSU logs so we can further check this for you. You may download it using this link: https://www.intel.com/content/www/us/en/download/18895/intel-system-support-utility-for-the-linux-operating-system.html. Additionally, were you able to have this wireless connection before? Have you also checked if this issue happens on different networks?

Ramyer M. 

Intel Customer Support Technician

[heistp]

The WiFi 6 (802.11ax) network where I see the problem is the only WiFi 6 network I have access to test. The access point is a Ubiquiti U6 Mesh with a wired uplink.

I do not see problems on my Linux box with the AX200 when connected to a WiFi 4 (802.11ac) network with an Airport Extreme as the AP. And as mentioned, the problem stops when I disable power management on the AX200 (iw dev wlp2s0 set power_save off). That makes me think it's related to the AX200 driver or firmware with WiFi 6 and power management enabled, or something else that makes it look like that.

Also, I do not see the same problem with different clients on the WiFi 6 network. For example, a MacBook Air, iPhone and iPad all work fine when using iperf3 with WiFi 6. It only happens on my Linux laptop with the AX200, and it happens right away every time I run iperf3, so it's consistent.

Thanks!

[RamyerM_Intel]

Hello heistp,

Thank you for sending it to us along with the additional information. We'll be looking at this inquiry internally for now and let you know in this post in case we need additional information or if a solution is already available. 

Ramyer M. 

Intel Customer Support Technician 

[RamyerM_Intel]

Hello heistp, 

Upon coordinating with my team, Since this is an OEM (Branded Laptop) original equipment manufacturer device, please take into consideration that our support may be limited since we are not familiar with the technology, settings, customizations, custom drivers, and features that the OEM has designed and installed your system. Seeing that you are running on Linux, we highly recommend checking out this link for additional guidance: https://www.intel.com/content/www/us/en/support/articles/000005511/wireless.html. If this does not work, we highly recommend reaching out to HP at this link: https://support.hp.com/us-en. The reason for this is because based on the specifications of the system, there is no mention of Linux. You may check it at this link: https://support.hp.com/us-en/document/ish_1865302-2473639-16 and verify with HP. You may also use this link to optimize your system based on their recommendation: https://support.hp.com/bg-en/drivers/hp-probook-455-g7-notebook-pc/32780046

Ramyer M. 

Intel Customer Support Technician 

[heistp]

Hi Ramyer,

It's very common that people use hardware that doesn't officially support Linux, but it works fine anyway. I think that is the norm rather than the exception, since most models don't have official Linux support. At least you are aware now of a problem with the AX200 in 802.11ax mode on this hardware in Linux, whatever the reason is...