Setting up Xmonad on a Lenovo ThinkPad X1 Carbon: Power Management and Sound (and Dead Ends)

This is my second post on the topic of setting up Xmonad on a Lenovo ThinkPad X1 Carbon. Previous post is here. This time around, we'll talk power management and screen geometry.

Power Management

Power management is handled by the xfce4-power-manager applet. I launch the applet in the .xsessionrc file, but when I initially launched it, it was invisible. It turns out, there were two issues:

1. By default, the tray icon doesn't show up. I had to enable it in the xfce-power-manager-settings app, which can be run from the command line.
2. The default icon in my desktop was black and I had it on a black background. That was easy enough to change out by adjusting the GNOME theme. lxappearance is the tool I used to do this; you can install it with apt-get and it then just runs on the command line. It allows me to tweak various configs, including the theming for icons; "Ubuntu-Mono-Dark" gave me a fine visible icon.

Not fancy, but it works

Once the power manager is in the tray, I can right-click on it and select "Power manager settings..." to configure the manager options. In particular, I make sure "When laptop lid is closed" is set to "Suspend" for both battery and plugged in modes. Note: this didn't work on the first try, and needed a restart to make it work. I can also use systemctl suspend to pause the machine, if needed.

Sound

Sound is notoriously complicated in Linux ecosystems. I tried a couple different options here and didn't find anything I'm completely thrilled with, but I did find some things I hated least. I ended up installing pasystray, which operates at the PulseAudio level. As a result, it's a bit options-heavy; PulseAudio lets you somewhat arbitrarily pipe audio sources to audio sinks, so I have the capability to, for example, send Zoom to my headphones while Chrome goes to my PC speaker (I don't want that, but I have it). My streams are also uhelpfully named "sof-hda-dsp HDMI1/DP1" etc. instead of, I don't know. "Computer speakers" or "Monitor output" or, uh, something sane. But it does work, and I can probably figure out (eventually) how to configure the human-readable device names.

"Sound is a solved problem in Linux"

Volume can be increased and decreased (on the default sink) via two-finger scrolling on the speaker icon (on the Carbon X1, Mod-volume-up and Mod-volume-down also work, since I configured them in Xmonad's keybindings themselves).

Final thoughts

I give this part of the configuration three out of five stars. Making the audio layer do anything that isn't space-alien is a real challenge when I step off the beaten path of Canonical's pre-configured tooling. But it is working, and I'm not unhappy with that.

Epilogue: Dead ends

Later update:I should mention some dead-ends I encountered while trying to configure everything. As always, one of the challenges of free software is there are so many options to choose from, and many aren't intended to work together.

Trying to install xmonad-extras from cabal

Directions here led me to try and configure volume control by installing xmonad-extras from cabal, the Haskell package manager. This was a detour; I later discovered the package was available in apt, but was named ligbhc-xmonad-extras-dev. Cabal isn't integrated with the apt packages in several ways (for one, its version of xmonad-extras installs in a different location that the apt install of Xmonad won't find them in; for another, xmonad-extras depends on a pile of C-written libraries that cabal can't install because it's not a universal package manager, it's only intended for Haskell code). Not worth the trouble

fdpowermon

For a brief period, I thought the power manager for xfce4-power-manager was buggy and didn't show an icon. The icon was there, but it was showing as black-on-black because of my icon theme. To work around this, I installed fdpowermon. fdpowermon has a couple of annoying issues: for one, it doesn't have a click-to-configure feature. But perhaps more annoying, the icon disappears when the laptop is plugged in and fully charged. This is a preference by the plugin's author; it can be overridden, but that's the default, to hide the whole thing! More trouble than it's worth; I uninstalled it.

volumeicon-alsa

Before settling on pasystray, I gave volumeicon-alsa a quick tour. This worked okay, but it didn't seem to want to let me switch my audio output devices. Also, I'm still a bit unclear on whether I want to be operating at the PulseAudio or ALSA layer of the audio stack. Rather than debug why internal laptop speakers, HDMI-accessible audio, and headphones weren't all showing up in volumeicon-alsa, I gave up and switched to pasystray... Even though the control it gives is overkill, it gives enough control that I can do what I want.