If your Wi-i.MX28 boots up with a boot log message like:
modprobe: chdir(184.108.40.206-del-220.127.116.11): No such file or directory
Loading ath6kl_sdio module: [FAILED]
ifconfig: SIOCGIFFLAGS: No such device
Starting dropbear sshd: OK
your WiFi interface will not work.
Root cause is, the WiFi driver ath6kl_sdio kernel module was not loaded, since the kernel version you build does not match an appropriate path in your root file system.
Fix: rebuild your root file system and deploy it to the module.
On a Wi-i.MX51 or Wi-i.MX53 similar message might appear reffering to ganges/redpine driver.