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I have a newish HP laptop with a Realtek RTL8821CE wireless network card. It didn't work right away when I installed Ubuntu 20.04, so I followed the instructions here with success, even though those instructions were supposedly limited to Ubuntu 18.04. Fast-forward to today: I ran "sudo apt-get autoremove" as a routine matter, and noticed a message from DKMS saying that the module was being uninstalled. I suspected that this would close down my computer's wireless connection abilities the next time I rebooted, and that did happen. I am really not sure why uninstalling old kernels and such should have prompted DKMS to completely remove a module I was using, but I tried following the steps in @ThomasAFink's answer again with my current kernel ("linux-modules-5.4.0-37-generic 5.4.0-37.41", I believe). The steps worked, but DKMS ended with a message saying:

Good news! Module version v5.5.2_34066.20200325_COEX20180712-3232 for 8821ce.ko exactly matches what is already found in kernel 5.4.0-37-generic. DKMS will not replace this module. You may override by specifying --force.

I guessed that it might be fruitful to revert to the kernel version that was removed by "apt-get autoremove", so I followed these steps to determine that it was 5.4.0-31-generic, and booted into that kernel to perform the same steps again. However, DKMS has given me the same message, and WiFi still doesn't work. I have a backup, Ubuntu 18.04 installed on the same computer, which does still support Wifi with tomaspinho's driver. However, there are a bunch of annoyances associated with reverting to 18.04 - older version of Emacs, which I use quite heavily, among others - and I would like to resolve this issue in 20.04 if possible. Any ideas?

Requested edit: The output of dkms status is:

rtl8821ce, v5.5.2_34066.20200325, 5.4.0-31-generic, x86_64: installed

I'm not able to get the output of 'uname -r' through chroot, but hopefully I have made it clear which kernel versions I am working with, above.

Requested edit: Here is a log from this morning of what I did. This log has the output of uname, dkms status, and everything else. In case you're wondering how git clone worked without internet access - I'm tethering my phone.

airbornemihir
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  • Please edit your question to add the result of the terminal command: `sudo dkms status` and also: `uname -r` – chili555 Jun 14 '20 at 23:20
  • It appears that the correct driver is built and installed in kernel version xx-31 only. Your original question says that it is *not* working in xx-37 or perhaps xx-41. It is difficult to repair without knowing what kernel version you are booted into. I admit that I am unfamiliar with the chroot environment. What does this tell us? `modinfo lp | grep file` It should tell you the current running kernel version. – chili555 Jun 15 '20 at 14:29

1 Answers1

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As we see from your paste, you followed both the sudo make install and the dkms process. That is what leads to the message:

Module version v5.5.2_34066.20200325_COEX20180712-3232 for 8821ce.ko exactly matches what is already found in kernel 5.4.0-31-generic.

In other words, dkms is not going to install it because sudo make install has already installed it.

These two methods are different ways to do the same thing; they need not be mixed and may result, as you've seen, in confusing results.

I suggest that you do:

cd ~/git/rtl8821ce
sudo make uninstall
sudo dkms remove rtl8821ce/v5.5.2_34066.20200325 --all

Confirm that it is removed:

sudo dkms status

It should return nothing. If so, try only the dkms process:

sudo dkms-install.sh
sudo modprobe 8821ce

Your wirless should now be working.

To install it for kernel version xx-37, the latest available, as far as I know, reboot into xx-37 and repeat:

cd ~/git/rtl8821ce
sudo dkms-install-sh

EDIT: In our chat we found this in your wireless info paste:

0: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: no

Soft blocked:yes typically means either that Airplane Mode is set to On in Network Manager or else in Settings > WiFi. After checking and toggling both, your wireless is now working properly.

chili555
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  • Thanks @chili555. I will respond further a little later after trying this out. – airbornemihir Jun 15 '20 at 16:31
  • Dear @chili555 unfortunately this didn't work for me; the wireless didn't come back on. I got your point about sudo make install colliding with ./dkms-install... so I did only the latter. See here: https://paste.ubuntu.com/p/zvR2mJGWYc/ I expect this to work because it did work with an earlier version - most likely 5.4.0-31-generic, which got uninstalled when I did apt-get autoremove - so it really flummoxes me that I'm unable to find my path back to making it work, sigh. – airbornemihir Jun 15 '20 at 22:51
  • Let's dig a little deeper. Please let me see a paste of: `lspci -nnk | grep 0280 -A3` and also: `dmesg | grep -i rtl` – chili555 Jun 15 '20 at 23:21
  • Thanks for sticking with this. Here is the paste you asked for: https://paste.ubuntu.com/p/dSZQ6KQtr8/ – airbornemihir Jun 16 '20 at 12:45
  • Here is evidence that the wireless is still hosed: https://imgur.com/a/Idrpn7r – airbornemihir Jun 16 '20 at 12:47
  • It shows a wireless interface, wlo1, was created. Is it improperly managed elsewhere than Network Manager? /etc/network/interfaces? Netplan? Does it scan and see networks? `sudo iwlist wlo1 scan` or else: `nmcli device wifi list` Are there any clues here? `dmesg | grep wlo1` – chili555 Jun 16 '20 at 14:11
  • @chil555 let me check with these commands. – airbornemihir Jun 16 '20 at 17:00
  • `sudo iwlist wlo1 scan` works in that it detects a bunch of wifi networks nearby, which I'll post only if needed because my neighbours probably don't need their wifi names out on the web... `nmcli device wifi list` doesn't show anything, which is surprising but probably not a problem. I looked up other AskUbuntu answers about NetworkManager not seeing a wifi card, but most of them, like your comment, pointed to /etc/network/interfaces which doesn't exist. Finally, the 1 line emitted by `dmesg | grep wlo1` is "[ 2.366168] rtl8821ce 0000:02:00.0 wlo1: renamed from wlan0". Any ideas? – airbornemihir Jun 16 '20 at 17:48
  • One more thing: I looked at the output of `journalctl -u NetworkManager`. It didn't tell me much, but it is here: https://paste.ubuntu.com/p/QwSW2d465m/ – airbornemihir Jun 16 '20 at 18:35
  • Let's also see a paste of: `cat /etc/netplan/*.yaml` If needed, please redact any personal details with xxxx. Also: `cat /etc/NetworkManager/NetworkManager.conf ` We know that NM is operating correctly as the USB connects as expected. By any chance, is Wicd installed? – chili555 Jun 16 '20 at 20:05
  • I ran both of those commands: https://paste.ubuntu.com/p/JzCpW958bQ/ Also, I ran `dpkg -l | grep wicd` getting no output. – airbornemihir Jun 16 '20 at 20:52
  • Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/109460/discussion-between-chili555-and-airbornemihir). – chili555 Jun 16 '20 at 23:44