mac80211: ath9k AP fails to honour client's power save mode
Username: Jean-Pierre Tosoni
Origin: https://bugs.openwrt.org/index.php?do=details&task_id=2391
Context:
I am using one device in AP mode, the other in client mode.
The client uses wpa_supplicant to do
background scan
to other channels that the data channel.
I am running iperf (UDP)
from the A
P to the client.
My device is home-made, Cavium development board-based, equipped with Compex WLE350NX.
It works correctly with kernel 3.18 and the 2015 wireless backport.
I updated to kernel 4.9 and the wireless backport 4.19.32-1, the last one from the trunk. (previously I used backport-2017-11-01 with the same result).
I am running wireshark with Airpcap to spy the wireless link.
Problem:
-
When the client scans offchannel, it correctly sends nullfunc frames around the offchannel period, with the PM bit set then unset.
-
However, during this time, the AP continues to send data to the client.
-
This results in a lot of lost frames, though I set the powersave buffers to high values on the AP side.
After some research I saw that the same kind of problem was fixed several times(*), but since there where so many changes in the queue management, I cannot really compare his work and the current state of the driver.
Any idea / patch / research directions ?
(*)