Performance degradation over time

[Michal Kazior]

On 8 March 2016 at 15:09, Matthew Keeler <mjkeeler7 at gmail.com> wrote:
>
> I have an arch linux box running kernel version 4.4 and within it two Airetos AEX-QCA9880-NX cards in it. I have hostapd configured to use one for 2.4 GHz bgn and the other for 5 GHz n/ac. After a fresh boot of the box I can get about 50Mbps over 2.4 GHz using iperf and 350-400MBps over 5GHz. After a couple of days or so the performance of my 2.4GHz card is dropping to about 5Mbps. Has anyone else had similar issues with this kind of performance degradation or does anyone know a good place to start to try and figure why this could be happening.
>
> A couple things I have checked: nothing in dmesg, nothing abnormal in hostapd logs, restarting hostapd doesn’t seem to help, only rebooting helps.

Hi,

You didn't mention firmware version that you're using:

  dmesg | grep ath10k.*firmware

>From the looks of it it seems like a firmware (probably rate control
module) issue and you can't do much in driver about that. At best you
could force firmware reboot via debugfs to workaround the problem:

  echo hw-restart > /sys/kernel/debug/ieee80211/phy0/ath10k/simulate_fw_crash

FWIW I suggest you to try out latest 10.2.4 if you didn't do that already, e.g.

  https://github.com/kvalo/ath10k-firmware/blob/master/QCA988X/10.2.4/firmware-5.bin_10.2.4.70.22-2

I guess you could also try getting fw stats after fresh boot and then
after the problem is observed and compare:

  cat /sys/kernel/debug/ieee80211/phy0/ath10k/fw_stats


Michał