Wifi stability under various wirless chipsets using Colibri Imx6 DL IT

We have tested the Colibri module with the following Wifi chips

  1. LM technologies - LM821 (Realtek RTL 8188CUS chipset) http://lm-technologies.com/product/wifi-smt-module-150mbps-with-ufl-receptical-lm821/
  2. Sparklan - WUBA-171GN (Atheros AR9271 chipset) http://www.sparklan.com/p2-products-detail.php?PKey=165dTr_MFn9dBglbfDIFMYEfkjdkOAcsBetxkHnXhA&WUBA-171GN

The first adapter from LM response stable and reconnects every time using connman.
The second adapters has the specs we need for our solution but stops auto reconnecting after a random timeout (could be hours or few days). We are using connman as the connection manger.

We already tried using a powered usb hub to rule out any power issues. The module is wireless connected to a WPA2/CCMT secured network. The accespoints are provided by HP and are centrally managed.

We are running on the latest V2.5B2 image.

Are there any known problems with the Atheros chipset in combination with the Colibri module or do you have any kind of suggestion?

We are not aware of any issues in combination with that Atheros chipset. However the only USB Wi-Fi stick supported out-of-the-box is the LM006 which can be bought through our online webshop.
As follows some general suggestion for bringing-up a Wi-Fi solution on an embedded Linux system: First make sure resp. solution runs stable on a regular PC running some LTS distribution with a similar Linux kernel version you plan to be running on your embedded system. This is also the place where you want to make sure you understand what exact firmware will be required. Then port this to your embedded system and make sure resp. driver, firmware and infrastructure (e.g. wpa_supplicant) versions are the same. Do start with encryption disabled and only enable encryption once your basic infrastructure runs stable.