Arch Linux

Empfehlenswert

Member

Registered: 2021-03-29

Posts: 3

Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

I am trying to install Arch Linux for the first time.

# uname -a
Linux LAPTOP-<my name> 5.11.10-arch1-1 #1 SMP PREEMPT Fri, 26 Mar 2021 00:11:29 +0000 x86_64 GNU/Linux

And I have troubles getting my rtl8821ce chip working properly.
I installed the AUR DKMS package
and blacklisted the current rtw88 driver implemented in the kernel 5.11

# cat /etc/modprobe.d/brokenWifi.conf
blacklist rtw88_8821ce

# lspci -k -s 07:00.00 | grep "Kernel driver in use"
Kernel driver in use: rtl8821ce

but as @corship stated here

The dkms module provided by this aur package does now work with the current kernel if you blacklist the rtw88_8821ce module in your /etc/modprobe.d/blacklist.conf.

so I tried getting the rtw driver to work.
blacklisted the aur driver:

# cat /etc/modprobe.d/brokenWifi.conf
blacklist 8821ce

The wifi chip is now using the rtw driver:

# lspci -v -s 07:00.0
07:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8821CE 802.11ac PCIe Wireless Network Adapter
	Subsystem: Lenovo Device c024
	Flags: bus master, fast devsel, latency 0, IRQ 142
	I/O ports at 4000 [size=256]
	Memory at a4300000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 3
	Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Capabilities: [70] Express Endpoint, MSI 00
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [148] Device Serial Number <16 digit long hex code "xx-xx-xx-xx-xx-xx-xx-xx">
	Capabilities: [158] Latency Tolerance Reporting
	Capabilities: [160] L1 PM Substates
	Capabilities: [170] Precision Time Measurement
	Capabilities: [17c] Vendor Specific Information: ID=0003 Rev=1 Len=054 <?>
	Kernel driver in use: rtw_8821ce
	Kernel modules: rtw88_8821ce, 8821ce

and it still does not work (as expected because it didn't work before the aur dkms module)

I searched online and even the same post by @corship is using the term "RFE 2"
I found out that people get error messages (link from here) if their "RFE" type is not supported, which outputs the "RFE" number. But I do not get anything like that, only this:

# dmesg | grep 8821
[   43.888856] rtw_8821ce 0000:07:00.0: Firmware version 24.8.0, H2C version 12
[   43.951608] rtw_8821ce 0000:07:00.0 wlp7s0: renamed from wlan0
[   44.463816] rtw_8821ce 0000:07:00.0: start vif <Serial Number 1> on port 0
[   44.465225] rtw_8821ce 0000:07:00.0: stop vif <Serial Number 1> on port 0
[   44.962177] rtw_8821ce 0000:07:00.0: start vif <Serial Number 2> on port 0
[  187.156929] rtw_8821ce 0000:07:00.0: stop vif <Serial Number 2> on port 0
[  187.651955] rtw_8821ce 0000:07:00.0: start vif <Serial Number 1> on port 0
[  187.698513] rtw_8821ce 0000:07:00.0: stop vif <Serial Number 1> on port 0
[  189.927959] rtw_8821ce 0000:07:00.0: no suspend buffer for PTM
[  191.787115] rtw_8821ce 0000:07:00.0: start vif <Serial Number 1> on port 0
[  192.104299] rtw_8821ce 0000:07:00.0: stop vif <Serial Number 1> on port 0
[  192.600493] rtw_8821ce 0000:07:00.0: start vif <Serial Number 3> on port 0

Is "RFE" referring to the "Rev=1" in? (if that is the case my card should be supported by rtw88 and I am doing something wrong):

# lspci -v -s 07:00.0 | grep "Capabilities: \[17c\]"
Capabilities: [17c] Vendor Specific Information: ID=0003 Rev=1 Len=054 <?>

or what do I need to look for to know if my chip is (not) supported?

everything with `<>` is edited by me with the exception of "<?>"

I am not the only one with this question apparently

Sincerely

Last edited by Empfehlenswert (2021-03-30 19:38:56)

ponyrider

Member

Registered: 2014-11-18

Posts: 112

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

Reading corships posts make me think that this will be fixed in kernel 5.12 (probably only two weeks away).. There is vanilla 5.12-rc5 availiable now

Best to watch this space rather than the AUR:
https://github.com/tomaspinho/rtl8821ce/issues/26

They have been speaking about this code for > one year now

Last edited by ponyrider (2021-03-30 02:44:11)

loqs

Member

Registered: 2014-03-06

Posts: 17,326

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

https://github.com/torvalds/linux/commi … c057d078d6 is the commit adding RFE type2 support.
Edit:
linux-mainline is available in Unofficial_user_repositories#miffe

Last edited by loqs (2021-03-30 03:35:56)

str0gg

Member

Registered: 2012-12-01

Posts: 75

Website

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

@Empfehlenswert

I had strange issue with this card is suddenly refuse to work with kernel range 5.10.4-5.10.19 and then is just got back to life (DKMS AUR package)...

Your  modprobe should look like this

/etc/modprobe.d/rtl8821ce.conf
blacklist rtw88_8821ce

Empfehlenswert

Member

Registered: 2021-03-29

Posts: 3

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

@str0gg
ah sorry. Made a mistake here (on my laptop it was correctly blacklisted with `rtw88_8821ce`) (edited in top post)

@ponyrider @loqs
If I have RFE Type2 I hopefully just need to wait for a few weeks. But I do not know if RFE Type2 is the case for me

I will ask over on https://github.com/tomaspinho/rtl8821ce/issues/26 about how someone can know their RFE Type without an error message.
I am going to post an answer here if I get to know anything.

Thank you very much for your feedback

Empfehlenswert

Member

Registered: 2021-03-29

Posts: 3

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

Apparently installing the https://github.com/tomaspinho/rtl8821ce driver with the provided

dkms-install.sh

script worked for me.

Before I installed it by
- cloning https://aur.archlinux.org/rtl8821ce-dkms-git.git
- cd into it
- makepkg
- pacman -U <created pkg path>

Now I
- removed it with

dkms -R

- cloned https://github.com/tomaspinho/rtl8821ce
- and ran the install script

I am glad my wifi is now working but the topics heading is not really answered. what does RFE mean (and how do I find out what type of RFE my chip is)?
(so I should not put a "\[solved\]" before the topics heading right now?)

cantabile

Member

Registered: 2010-06-29

Posts: 33

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

How to know for sure what RFE type you have? I had a look at the code now and apparently the only types currently supported are 0 and 2. Support for type 2 was added in Linux 5.12, so if you boot an older kernel it will either work (or "work") if you have RFE type 0, or it will print an error message with the RFE type.

There is also RFE type 4, which is still not supported.

I don't know what "RFE" means.

cantabile

Member

Registered: 2010-06-29

Posts: 33

Re: Meaning of RFE (WIFI Chip - rtl8821ce) (and driver troubleshooting)

I have learned what RFE means: „RF front end”.

https://lore.kernel.org/linux-wireless/ … altek.com/