Disconnected due to excessive missing ACKs on Ath10k (OpenWRT Chaos Chalmer RC2)

[Fernando S]

I'm having dropouts on my TP-Link Archer C7, 2.4Ghz Wlan runs perfect,
but 5Ghz is unstable (my laptop and my Ipad 4 loss connection after a
couple of minutes, specially on heavy traffic).
Looking on router's log, I found:

Thu Jul 9 20:51:32 2015 daemon.info hostapd: wlan0: STA
01:02:03:04:05:06 IEEE 802.11: disconnected due to excessive missing
ACKs Thu Jul 9 20:52:02 2015 daemon.info hostapd: wlan0: STA
01:02:03:04:05:06 IEEE 802.11: deauthenticated due to inactivity
(timer DEAUTH/REMOVE)


And on client side:

Jul 9 20:51:05 laptop wpa_supplicant[1011]: wlan0:
CTRL-EVENT-DISCONNECTED bssid=30:30:30:30:30:30 reason=7 Jul 9
20:51:05 laptop NetworkManager[861]: <warn> Connection disconnected
(reason 7)
A little search on Google show me some old bugs, apparently resolved
and only on ath9k (2.4Ghz): maybe the same issue is present on ath10k
(5Ghz)?

Please let me know if I can help to debug this issue.

Thanks and regards.