RTL8822BU and RTL8821CU USB drivers

Hello,

I have some RTL8822BU and RTL8821CU USB devices that want to use with OpenWRT, but I can not find the way to get they working.

I try to install kmod-rtl8xxxu package, but it doesn't work.

Anyone know how could I get them working?

I will appreciate your help.

Kind regards.

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By replacing them with something that isn't made by Realtek.

Thanks for the reply, but I have thoose devie, so I don't want to buy others.

Could be possible to make a pull request about this repo?

It will be great to get this driver in all images.

Regards.

yeah that's not very likely ....

there's a reason why RTL wireless is a no go zone ....

Hi,

which is the reason?

Best regards.

All current out-of-tree Realtek drivers suffer from deadlock when deleting the interface with iw dev wlan0 del.


And this is exactly what OpenWrt does during AP configuration.

Either the driver or mac80211.sh OpenWrt script should be patched.

These are (unsurprisingly) bugs in the realtek wireless drivers and need to be fixed there, chances that OpenWrt will be changed to workaround driver bugs (especially for drivers that aren't even used in any supported devices) are minimal.

There is an ongoing effort to bring rtl882bu and rtl8821cu (and other rtl chipsets) into the Linux kernel. See here:

Since OpenWRT is based on the Linux kernel, all you will need to do is to wait until kernel 6.2 (or something) has reached OpenWRT (or to help porting the 6.2 kernel to OpenWRT). From what I can hear, these in-kernel drivers may still need a little refinement though. They are also mainly pushed forward by volunteers. Any help is welcome, as (to my knowledge) Realtek has refrained from doing so. Unfortunately, Realtek is not one of these companies that at present time upstream their wifi drivers to the linux kernel. I own a 88x2bu, but next time I buy a device, I will take care to choose one that is supported in-kernel.

For now, your best bet would be to install an out of kernel driver. You will not be able to use OpenWRT with them, but these out of kernel drivers may be enough, if your use case is that of a simple wifi client. Sometimes they even support accesspoint (AP) mode or monitor mode.

Out of kernel drivers that are installed via dkms (these drivers need to be upgraded/removed before any attempt to upgrade to a newer kernel):

As I mentioned above, these drivers hang upon deleting the interface, which OpenWrt does internally. It works if you patch mac80211.sh, but that's not a solution for everyone.

Unfortunately, at least with rtl8821cu, rtw88 does not work properly for 2.4 GHz. It either selects incorrect antenna or does not enable power amplifier properly, at least for me. I already contacted the authors.

Backported drivers are available here: https://github.com/lwfinger/rtw88

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This has been fixed in rtw88. The backported drivers now also include these commits.
Tested with RTL8811cu, works fine.

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