Running Linux on my Thinkpad Z13 Part 2: Arch

I really enjoyed pop_os! on my Z13, but I was experiencing some issues when docking the laptop with multiple monitors (frequent crashes, hang-ups). I was also just curious about using an Arch based distro and an updated version of Gnome, so I installed Endeavour OS.

I’ve had to make enough adjustments that I think another post is warranted.

Battery #

While battery life was okay with just power-profiles-daemon (included with Gnome by default), it didn’t seem to be quite as great as I thought it could be when doing low power tasks like basic text editing in the terminal. Because of that, I uninstalled it and installed tlp like so:

# Useful guide: https://linrunner.de/tlp/faq/ppd.html
yay -R power-profiles-daemon
yay -S tlp
sudo sed -i "s/#\?PLATFORM_PROFILE_ON_AC=.*/PLATFORM_PROFILE_ON_AC=performance/1" /etc/tlp.conf
sudo sed -i "s/#\?PLATFORM_PROFILE_ON_BAT=.*/PLATFORM_PROFILE_ON_BAT=low-power/1" /etc/tlp.conf
systemctl enable tlp.service
systemctl mask systemd-rfkill.service systemd-rfkill.socket
echo "Run sudo tlp start or restart"

If you’re on the Z13, then the platform profiles should work fine for you, but if not you can run sudo tlp-stat -p to see what your options are.

Anyways after these changes I’m seeing a drastically improved battery life for low-powered tasks (5-6 hour estimates became 8-10 hour estimates when around 75-85%). This seems more in line with what I was getting on pop_os!.

Sleep Issues #

The biggest sleep issue I had was that sometimes the laptop just wouldn’t wake up or go to sleep properly. E.g. one time I had an experience that resembled a common issue found on Windows laptops with Modern Standby. I closed the lid and put the laptop in its case, only to return and find a hot laptop with an unresponsive black screen that I had to force shutdown. This was pretty rare and I didn’t notice any obviously actionable logs in journalctl, but it didn’t feel great. It seemed to be exacerbated when docking/undocking the laptop, but I never figured out a root cause.

Fortunately, the troubleshooting section of the relevant arch wiki page ¹ gives downgrading to the LTS kernel as an unofficial solution, and it seems to be working for me. All I had to do was run yay -S linux-lts to install the LTS latest kernel, and it was automatically added as the top option of my systemd-boot menu.

Wi-Fi Slowdown #

The issue where the WiFi speeds dip dramatically after sleep also returned. My fix this time around is very similar to the last one I posted.

I copied this script:

#!/bin/sh

PATH=/sbin:/usr/sbin:/bin:/usr/bin

case "$1" in
	# code execution BEFORE sleeping/hibernating/suspending
	pre)
	;;
	# code execution AFTER resuming
	# Idea from the following blog post:
	# https://null.rip/2022/09/linux-on-the-thinkpad-z13-all-amd-almost-there/
	post)
		echo "Toggling wlan twice"
		rfkill toggle wlan
		rfkill toggle wlan
	;;
esac

exit 0

to /usr/lib/systemd/system-sleep/². You can name it whatever you like, it just has to be executable. I figured deleting the module like I posted before was overkill since the problem is also solved by just toggling the Wi-Fi on and off.

Despite adding this script and confirming that it runs on resuming from sleep, I still notice the internet speed slowing from time to time. Turning the wlan on and off manually fixes it, it’s just annoying!

Fingerprint Sensor #

As before I started with installing fprintd (yay -S fprintd). Just doing this enabled Gnome’s fingerprint support and the lock screen worked well.

The pam files were different on Arch so I had to do a little bit more digging to get the fingerprint scanner working well for authing other requests. There wasn’t a magic command to run that just figured it out for me (which was awesome on pop_os! and I wish there had been one in this case), but the Arch wiki³ was extremely helpful as always.

For my first attempt to get fingerprint auth working with sudo, my /etc/pam.d/sudo looked like this:

#%PAM-1.0
auth	  	sufficient 	pam_fprintd.so # addded line
auth		include		system-auth
account		include		system-auth
session		include		system-auth

This didn’t work super well with yay, as I’d press Ctrl+C to get past the fingerprint auth (when using the laptop docked, for example), and the whole program would just exit. This behavior would also trigger pam_faillock, locking me out of authing any sudo commands for 15 minutes each time. Super annoying.

Reading just a little further down on the page, I removed the above edit and instead edited /etc/pam.d/system-auth like so:

#%PAM-1.0

# deny=10 because the default of 3 is constantly getting me locked out
auth       required                    pam_faillock.so      preauth deny=10
# the next 3 lines are the main change. If pam_unix receives nothing, we try
# fingerprint auth.
-auth      [success=3 default=ignore]  pam_systemd_home.so
auth       [success=2 default=ignore]  pam_unix.so          try_first_pass nullok likeauth
auth       [success=1 default=bad]     pam_fprintd.so
auth       [default=die]               pam_faillock.so      authfail
auth       optional                    pam_permit.so
auth       required                    pam_env.so
auth       required                    pam_faillock.so      authsucc

# The rest of the file was left unchanged

As you can see, rather than try to auth with the fingerprint first, we first try to auth regularly and allow the stack to continue normally if an empty password is supplied. This means that whenever I want to use my fingerprint, I can just press Enter first. I can live with that.

There is one caveat to note: system-auth is included in a ton of other places, so this may not be the most secure option, but I think I’m fine with allowing most situations to be authorized using my fingerprint when possible.

Debugging Tip #

One factor that confused my debugging process was the fact that my keyring password was set to the password I used to encrypt my disk. I’m not sure if I did that or the installer did, but I initially thought that this behavior was another symptom of triggering the lockout. I ended up installing seahorse (yay -S seahorse) to change the password on my keyring to what I expected it to be (the same as my login password set via passwd). This works until I restart, and then it’s set back to my LUKS password. Not sure how to change this but I don’t mind it I guess.

Laggy Touchpad #

I find that sometimes my touchpad is extremely laggy, and it seems significantly worse when I turn on my laptop while connected to power. If I disconnect my AC adapter and reboot, the touchpad returns to normal.

Skimming the internet, it seems like it could be because I’m using a cheap USB-C charger I bought in another country. I also noticed the problem in Windows when I went to check if the problem was due to a missing firmware update (there were some updates available, but they didn’t fix the issue).

I don’t really have a ton of insight for this one, I’ll just go back to using my good chargers when I get back home ¯_(ツ)_/¯

Misc #

auto-cpufreq #

This post⁴ mentioned using auto-cpufreq, but it didn’t work for me. For some reason when I had it enabled the trackpoint would register random right clicks when the laptop was docked.

mDNS #

To get mDNS working (the feature that enables you to go to a host-name.local service you may be running on your LAN), I had to:

1. Open the firewall application and assign my network to the “home” zone, where mDNS is enabled by default. I figured this out while browsing this Endeavour OS wiki page.

   Example:

   

2. Enable a daemon that provides mDNS. I used Avahi, so I followed the instructions here. You should also be able to use resolved following the instructions here (it just seemed like more work).

Brave & Wayland #

If you’re using brave-bin from the AUR, then you can add any Brave flags⁵ you want to use permanently to $XDG_CONFIG_HOME/brave-flags.conf. Here’s what I use to make Brave use Wayland and allow the two-finger swipe gesture to go back and forth in history.

--gtk-version=4
--ozone-platform-hint=auto
--enable-features=TouchpadOverscrollHistoryNavigation
--ozone-platform=wayland

The ozone-platform setting makes the title bar weirdly smaller, but that’s the only downside I’ve noticed. Ultimately, I switched back to Firefox (specifically Librefox) since it worked well with Wayland out of the box.