Ath10k with HostAPd very slow

[Conrad Kostecki]

Hi!
I've replaced both of my ath9k cards (Compex WLE350NX) with new ath10k cards (Compex WLE900VX). But it seems, I've some sort of performance problems. With the new cards, the connection from clients is very slow. The throughput, while connected with an Intel 6300 is about 3-6mbit (measured with iperf). My Nexus4 is even slower with about 1mbit. It doesn't matter, if it's on 2.4GHz or 5GHz. Windows shows in the connection properties, while connected to the 2.4GHz WiFi about 350-450Mbit. On 5GHz it seems to be slower, as it shows about 150Mbit, sometimes up to 250MBit. It's goes up to 450Mbit, if I disable 802.11ac in the configuration of hostapd. Both tests are done directly in front of the AP. I've only noticed, that in 5GHz band with 802.11ac enabled, if shows one channel and according to debug log with 80MHz bandwith. In 802.11n mode only I can see two channels, with a bandwith of 40MHz.

2.4GHz startup debug log: http://pastebin.com/whxKqjWP
5GHz (802.11ac disabled) startup debug log: http://pastebin.com/LGpYUWZc
5GHz (802.11ac enabled) startup debug log: http://pastebin.com/CdP3PVw8

So, what can I do to speed up my WiFi, to make is fast, as it was with my old ath9k cards? I would expect at least 70-80Mbit in 802.11n mode, as 5Mbit can't be normal.
Does anybody has some ideas? Can I debug this somehow?

Kernel: 3.16.1
[    4.113905] ath10k: qca988x hw2.0 (0x4100016c, 0x043202ff) fw 10.1.467.2-1 api 2 htt 2.1
[    4.351541] ath10k: qca988x hw2.0 (0x4100016c, 0x043202ff) fw 10.1.467.2-1 api 2 htt 2.1

2.4GHz configuration: http://pastebin.com/wyuCkXZe
5GHz configuration: http://pastebin.com/y3u53Zzs

Thanks!
Conrad