Just adding, I had good results using ath10k drivers and adding "intel_iommu=off" to the kernel parameters. My WiFi card is AR9462 which normally uses ath9k drivers, but the ath10k drivers work just as well with that added kernel parameter I listed. Also to note, OpenVPN isn't reliable at all with this configuration so if you need a VPN you could try using L2TP/IPsec protocol instead, that has worked for me.
