How to add drivers for RTL8811cu to OpenWrt

Hi, I am using openwrt with TP-Link TL-WR1043ND v1. I've just got a RTL-8811cu USB network adapter that I'd like to connect at the USB port but I did not find adequate drivers.

I noticed there are linux drivers for this device at https://github.com/brektrou/rtl8821CU

I don't know how difficult could it be to use this driver with my hardware platform, this is why I am posting here, in order to get some orientation about this subject.

Thanks!

Mauricio

That's a slightly butchered up vendor driver, which isn't compatible to nl80211 (still using its own kernel 2.6.16 derived ieee80211softmac wireless stack) - as a consequence AP mode won't be possible, even if you package up that driver. Furthermore USB throughput on your router is around 4 MByte/s, a far cry of the speed 802.11ac requires (you'd probably run into OOM conditions as well, as your second radio will need quite some RAM as well).

If you have a little patience while checking your local used markets, you may find quite decent OpenWrt supported concurrent dual-band 802.11ac routers for surprisingly cheap prices (~20 EUR or USD, less if you're lucky).

Hi, thank you for your answer.

I don't need AP mode. I just want to use this tiny adapter to link in client mode to a distant location. Reduced bandwidth isn't a concern neither. I'm lost at how to get that driver working in my own router.

You will have to package it up as an OpenWrt (source-) package, similar to the others. Pretty much by definition the USB WLAN card will have worse reception characteristics than using the native WLAN capabilities of your router (much smaller antennas, too close to each other); this won't actually help you.

Hi, thanks for the comments.

This adapter has an sma-rp connector where you can attach any antenna you like.

Let me see if I am understanding: Do I have to upload the source code for the driver to a repository and wait for it to be compiled and available for my platform?

No, you can (and need to) start with local modifications of the repo and build it yourself.

Recent Realtek chipsets such as RTL8812AU actually supports AP mode, but since it is a cfg80211/nl80211 driver, it probably does not work with LuCI. You may need your own script to bring up the device and run the hostapd instance.

@mautas
You can refer to the rtl8812au-ct package and see if you can package the rtl8811cu driver for OpenWrt.

EDIT:
According to Jes Sorensen's presentation, Realtek's development process is like:

1. Respin hardware
2. cp -a driver-<oldchip> driver-<newchip>
3. Hack driver-<newchip>
4. Release driver-<newchip>
5. goto 1