ZenLinux Blog

I recently got a new laptop, a Thinkpad T14s Gen6 (Intel version), and I was disappointed to find that the touchpad had a slightly “loose” feeling to it. When I’d place my finger on the touchpad, I’d feel a tiny bit of vertical play, and it really cheapened the experience of using the touchpad.

I knew this wasn’t the way the touchpad should be behaving, but I didn’t want to return the laptop for RMA/repair. In researching this issue, it appears to have been quite common on the T14 series laptops, especially back during the Gen3 version of it. I found a few Reddit posts of folks discussing the problem and a potential fix for it by using a piece of tape to shim a small gap in the touchpad’s assembly. Since the posts I found are specific to an older version of the T14/T14s, I thought I’d just share some photos of what I did to fix it so anyone else encountering the problem can take care of it themselves if they wish.

Standard disclaimers apply here – I’m not responsible for any damage you do to yourself or your laptop by following these instructions. Do this at your own risk.

Step 1: Go into the BIOS settings and disable the built-in battery. I actually didn’t bother to do this, but it’s probably a good idea to do it and be on the safe side.

Step 2: Remove the bottom case. There’s a great video demonstrating how to do this on the T14s Gen6 on YouTube:

The main thing to keep in mind is to start opening the case from the back of the unit (where the hinges are) and work your way to the front. You should eventually be able to lift up the bottom panel without having to use your pry tool along the front edge.

Step 3: Disconnect and remove the main battery. There battery connector is a bit finicky to disconnect and reconnect, and again there’s a great video demonstrating how to do it on YouTube I’ll refer you to, since a picture (or video) is worth a thousand words. While this video is for the Gen2 version of the T14s, the battery removal process is pretty much identical – about halfway through this video is where the demonstration of disconnecting the power connector is shown:

Step 4: Once you remove the battery, the touchpad areas is covered by a black sticker. You don’t need to remove any of the ribbon cables, just carefully peel back the lower half of the sticker to expose the area where the touchpad play exists. I’ve marked them with red arrows. In my case, the play was primarily on the left side of the touchpad, and I only needed to add a shim to that side (which is on the right side when the unit is upside-down, as in the photos below):

Step 5: Now find a shim material that is thin enough to fit into this corner area, but just rigid enough that you can slide it in without the material crumpling up. I found a piece of a 3×5 index card was perfect for this, but your situation may vary based on how much space you need to shim. Once inserted, I trimmed the paper and taped it down to secure it:

Step 6: Put everything back together. The battery power connector is again a bit counter-intuitive to use, so refer to the video above which demonstrates how to reconnect it.

So far this fix is working great for me and the touchpad now feels solid and stable, and I can still press to click normally too. One thing I’ll mention though is that I can see the section of 3×5 card in the gap at the edge of my touchpad. If this bothers you, use a black-colored shim to minimize the visual impact.

I hope this helps some of you out there who run into the same problem!

I have several audio devices connected to my Linux desktop machine, including a USB audio interface (a MOTU M4), and a Jabra wireless headset that uses a USB dongle, and appears as its own audio device. I also like to use Bluetooth headphones on a daily basis.

After switching to Pipewire as my audio backend, I found that my default audio device wasn’t switching automatically to what I wanted – I’d always have to set it manually. I’d need to do this when my BT headphones would connect (select the a2dp headphone profile), and then again when I disconnected them (because I wanted to hear sound from my MOTU audio interface, but it would automatically fallback to the Jabra headset device). This is a two-part recipe to fix these issues.

Step 1: Make pipewire automatically select my Bluetooth headphones sink when they connected. This didn’t require any configuration changes. Instead, I have a script which runs on startup of my desktop environment which runs pactl load-module module-switch-on-connect. This is actually a pulseaudio command, but desktop apps still use the pulseaudio interface, which pipewire implements as part of the pipewire-pulse package.

Step 2: Make my default audio device my MOTU M4 audio interface, and stop selecting the Jabra headset device when I disconnect my BT headphones. This turned out to be caused by the fact that the Jabra audio device had a higher priority than my audio interface. Run the command wpctl status to show a list of your audio devices, and make a note of the device number. In this case, I was looking for the M4 device in my list of Audio Sinks. Then you can run wpctl inspect <device-number> to show the details of this audio device. What you’re looking for are the fields priority.driver and priority.session. Larger numbers correspond to a higher priority, but for sinks, they should be kept no larger than 1500 (otherwise a sink’s monitor could end up being selected as a default source – this is called out in the Wireplumber documentation). In my case, the Jabra sink had a priority of 1008, so I chose to set my audio interface to a priority of 1050.

Update May 2024: Wireplumber as of v0.5 no longer uses lua scripts for configuration. Check which version of wireplumber you’re using, and if you’re on 0.5, please refer to this guide to update the lua script below to the new format (and file location). I’ll update this blog post further when I have the time.

To change this configuration, you’d do so in Pipewire’s session manager. The preferred session manager for Pipewire is Wireplumber, which uses lua scripts to apply these kinds of custom configurations. So in my case, I created the file ~/.config/wireplumber/main.lua.d/60-raise-motu-m4-priority.lua with the following code:

rule = {
  matches = {
    {
      { "node.name", "equals", "alsa_output.usb-MOTU_M4_M4MC0570FU-00.Direct__hw_M4__sink" },
    },
  },
  apply_properties = {
    ["priority.driver"] = 1050,
    ["priority.session"] = 1050,
  },
}

table.insert(alsa_monitor.rules,rule)

Then, restart the wireplumber service with systemctl --user restart wireplumber and compare the new output from wpctl inspect. You should now see that the driver and session priorities are what you set them to. And when pipewire automatically switches to a new audio device, the highest priority device should be chosen.

I’ve found Pipewire and Wireplumber’s documentation to be confusing, and there are lots of dead-ends you can go down when researching how to do this. I hope this recipe-style blog post is easier to understand if this is the problem you’re trying to solve.

Many thanks to PleasantlyFlailing on the r/linuxaudio subreddit for suggesting some improvements to this blog post!

I’ve recently made the switch to using Pipewire on my Linux desktops. One thing I noticed in my list of audio devices was an entry for my HDMI monitor, which I never planned to use. I also do some music production on my Linux machines, and disabling this audio device would help my patchbay configurations look a bit cleaner.

Pipewire’s documentation is pretty basic, and when searching for this solution online, I went down several incorrect paths. We could really use more recipe-style examples on the web, so here’s mine. This is done using the Wireplumber session manager.

First, identify the audio device to disable using pactl list short. In the output from this, I could see an entry for the audio sink (alsa_output.pci-0000_27_00.1.hdmi-stereo-extra2.monitor) and for the audio device (alsa_card.pci-0000_27_00.1). It’s the alsa_card device that you want to disable, not the sink.

Update September 2024: Wireplumber as of v0.5 completely changed their configuration format from lua to json, and won’t automatically migrate your configuration. Before proceeding, check which version of Wireplumber you have installed.

For Wireplumber < 0.5, the configuration format is lua scripts. For this example, I created the file ~/.config/wireplumber/main.lua.d/51-disable-hdmi-devices.lua with the following code:

rule = {
  matches = {
    {
      { "device.name", "equals", "alsa_card.pci-0000_27_00.1" },
    },
  },
  apply_properties = {
    ["device.disabled"] = true,
  },
}

table.insert(alsa_monitor.rules,rule)

For Wireplumber 0.5 and later, the configuration format is json. For this example, I created the file ~/.config/wireplumber/wireplumber.conf.d/51-disable-hdmi-devices.conf with the following code:

monitor.alsa.rules = [
  {
    matches = [
      {
        device.name = "alsa_card.pci-0000_03_00.1"
      }
    ]
    actions = {
      update-props = {
        device.disabled = true
      }
    }
  }
]

Then, restart the wireplumber service with systemctl --user restart wireplumber and this audio device should now be gone – you won’t see it in your sound settings or in your patchbay diagrams.

On more than one occasion, I’ve found that the device names have changed after a major update – I’m not sure if this is due to a kernel change or a change in pipewire/wireplumber. But if things suddenly stop working and you’re seeing devices you thought you had disabled, go back to running pactl list short and see if your device name has changed.

For reference, I’m using pipewire and wireplumber on Manjaro Linux, which is a rolling release distro and tends to stay pretty close to the upstream software releases. I ultimately learned how to do this via the Arch Wiki page for Wireplumber, though at first I got confused about the need to specify an audio device instead of a sink. That caused me to think this was the wrong solution, and I spun my wheels for more than a week trying other things (e.g, turning the device profile off in pavucontrol) which didn’t work. Another handy reference for the wireplumber 0.5 config change update is this migration guide. Best of luck with your audio configuration journey!

Mozilla’s Firefox web browser and Thunderbird e-mail clients have a little-known feature known as “Profiles.” Profiles allow you to create fully separate instances of these applications, each with their own customized config preferences and extensions.

I make heavy use of this feature to create separate Firefox profiles for my personal everyday web browser, work web browser, web development browser, etc. With Thunderbird, I use profiles to separate my personal vs. work email.

From the command line, invoking firefox or thunderbird with the -P option will bring up a dialog box, allowing you to chose between your existing profiles, or create/rename/delete profiles:

If you haven’t created any new profiles, you’ll be using a profile named default. On my Ubuntu systems, each of these profiles will be stored under your ~/.mozilla/firefox/ directory (for Firefox) or ~/.thunderbird/ directory (for Thunderbird).

If you want to be able to easily launch these profiles from the GNOME Shell GUI rather than the command line, you can create custom launchers for each profile. I typically do this and choose different icons for each profile to visually tell them apart. To do this, create a .desktop file within your ~/.local/share/applications/ directory. I typically name these files firefox-<profile-name>.desktop. Here’s an example of one:

[Desktop Entry]
Version=1.0
Name=Firefox (WebDev)
Exec=firefox -P webdev -no-remote --class FirefoxWebDev
Comment=firefox
Terminal=false
Icon=/usr/share/icons/oxygen/base/128x128/categories/applications-development-web.png
Type=Application
StartupWMClass=FirefoxWebDev

By default, the Icon setting will search for an icon file (e.g, .svg or .png file) from your current theme within your /usr/share/icons/ directory. Specify an absolute path to the icon file and include its filename extension if you want to use an icon that’s not in your current theme. You can also create custom icons and drop them in your ~/.local/share/icons/ directory.

Note that on the Exec line I’m also starting firefox with two additional options, -no-remote and --class. The -no-remote option prevents conflicts with other instances of Firefox that are running. The --class option specifies a window manager class, which you’ll also set for the StartupWMClass option. You can set this value to any string you like, but it must be unique (i.e, don’t re-use it in another .desktop launcher config).

If you don’t set a custom window manager class, all of your running profiles will be grouped together under the same icon in the GNOME Shell panel. That last subtlety has been an annoyance I’ve wanted to fix for a long time, and learning about it is what prompted me to write this post to share.

References: Mozilla docs on using the profile manager, AskUbuntu post on setting the window manager class

I’ve been taking a self-funded sabbatical from work this summer, and set out with a bucket list of things I’ve always wanted to get around to doing but never felt I had the time to fully dive into. One of those things was to take a Ruby on Rails based task manager that I’ve been using personally for the past year and refine it as needed so I could launch it as a legitimate production-level application.

What does production-level mean to me? In this case, a bunch of things:

• The app needs to have solid multi-user support with account registration, password resets, etc.
• Testing and Test Driven Development should be taken seriously. Unit, integration, and selenium-based system tests should reach well over 90% code coverage.
• The code should pass linting tools such as rubocop and rails best practices, as well as security auditing tools such as brakeman
• The code deployment process should be simple, capable of rollbacks, and automatable (I’m using capistrano)
• The server infrastructure that ProgressPuppy relies on should be easily replicable at the push of a button (using infrastucture as code tools such as Terraform and Puppet)
• The application should have a robust backup and restore process
• I should be able to keep the application up to date with the latest stable versions of Ruby on Rails and its dependent gems (the app is currently running on Rails 6.0)
• Use Stripe to accept payments for paid plans
• Deploy a marketing web site to showcase what ProgressPuppy does and its various plan tiers

The point of this hasn’t been to create a side project that generates significant income – I don’t mind at all if no one but me and a handful of friends ends up using ProgressPuppy. Instead, I wanted to go through the exercise of treating the web app more seriously, but keeping it within a limited scope where the learning would remain fun.

To say that this effort took up a lot of time would be an understatement, but the fun factor remained strong the entire time. I use this tool as my daily task manager, and the various memes that pop-up after completing tasks still bring a smile to my face:

Check out ProgressPuppy if you get a chance. I don’t pretend to have much in the way of web design skills, but the web app is functional and reliable, and I intend to keep it that way as I make further improvements to it. Next on my roadmap is to introduce some daily habit tracking features and make the app more mobile web browser friendly.

ProgressPuppy is also open source software, released under the GNU Affero GPL license. You can find its source code repo on GitLab.

I returned to China during a three country East-Asia trip this Spring, and thought I’d share some more notes on being able to work remotely while in China. Some things worth sharing have changed since my last blog post on the topic in 2016.

One thing that’s interesting about the Great Firewall (GFW) is that China uses it for censorship of its mainland residents, but doesn’t do so for residents of Hong Kong, even though many of the same Chinese telecoms offer services there. I’ve heard that if you buy a prepaid sim card in Hong Kong, and use it in mainland China, your cell data service is not blocked by the GFW. So I was going to buy a prepaid Hong Kong sim before my trip until I learned that you can also buy sim cards from foreign providers that can work at 4G speeds in roaming mode in multiple countries. As I was traveling to Japan, Korea, and China, I started looking for a single sim solution that would work in all three countries.

What I found (and which worked flawlessly) was the AIS sim2fly prepaid sim card, which you can buy on Amazon. AIS is one of the biggest telecom companies in Thailand, and they claimed that these cards worked at full 4G speeds in roaming mode in several Asian countries, and that the service was not blocked by the GFW when used in China. They offer an 8-day prepaid sim with 6 GB of data (tethering supported), which was more than enough data for me. I ended up buying a few of these, so that after 8 days I simply popped in a new sim card and I was good to go for another 8 days. On top of that, using these sim cards was cheaper than if I were to have bought separate sim cards for Japan, Korea, and China. I’d highly recommend the AIS sim2fly prepaid sims for these kinds of trips.

As for the times I had to use a VPN over wifi, I did some more research and learned that Astrill is still a reliable provider. As of late, ExpressVPN seems to have become mostly unusable in China based on my research, though I didn’t try to use it personally during this trip. Anytime I had to use Astrill (which I typically used in their Wireguard mode), my speeds were extremely slow (1-2 Mbps) compared to what I’d get tethered to my smartphone AIS connection. Also my VPN would disconnect at random times – sometimes it would work reliably for a half-hour or more, and other times it would disconnect every few minutes. So my advice is if you don’t need to stream a lot of data, it would be far more convenient to rely entirely on smartphone tethering for your internet needs, assuming you’ve got good cell data coverage in the area you’ll be visiting. For any major city in China, this will be a non-issue.

An unrelated observation I had while in Beijing was that none of the locals used cash – everyone paid for things using WeChat Pay.
Unfortunately, you can’t link a foreign debit card to your WeChat Pay account – it only works with cards issued by Chinese banks.
So I was often the annoying foreigner who paid for things with cash. At one bakery, they even refused to break a 100 RMB note (worth around $14 USD) because they didn’t have enough change in their register. Being able to use WeChat pay unlocks a lot of other conveniences you can use in China, such as Didi (their equivalent of Lyft/Uber) rideshare payments, bike rentals, etc. So if you’re going to be in China for a long time (e.g, over a month), it may be worth the effort to open a Chinese bank account and keep a small amount of money in it for use with WeChat Pay.

Last month I visited Beijing, China and had to work remotely during my trip. At work we rely on a number of Google services, so I needed a reliable way to circumvent the Great Firewall of China (GFW). After doing a decent amount of research, I learned that just running a SOCKS proxy via SSH is likely to run into problems, so I used a couple of commercial VPNs, as well as a private Shadowsocks server I had set up on various ports of a Digital Ocean droplet. The idea being to have a couple of fall-back methods to tunnel through the GFW in case my primary one stopped working. I thought it might be useful to report on what worked well, and what was most challenging about this.

Given that I’m a Linux user and needed solutions that were Linux-friendly, I settled on two highly recommended commercial VPNs – ExpressVPN and Astrill. I also sprung for the added “VIP” add-on to Astrill that gives you access to a few additional VPN endpoints that presumably have lower utilization. In summary, Astrill was the clear winner, especially with the VIP add-on. Though no matter which VPN service I was using, there was a lot of fiddling that had to be done to test the latency of different proxy endpoints. There wasn’t one I could just set and forget.

Finding usable wifi in Beijing is another story, and proved to be a frustrating problem. My local resident friend told me that the Chinese tend to use the internet for recreation rather than getting work done, so the vast majority of folks packed in coffee shops are streaming video to watch movies or TV shows. My own observations backed this up, and it was easy to notice this, as a sizable proportion of these folks don’t bother to use headphones when watching their entertainment (grumble). So I found the only times I had really solid wifi speeds were when I found a coffee shop that was mostly empty, and probably half the time I gave up on the wifi and just tethered to my phone’s data connection. For most of my work I was running remote builds over SSH, and I found my phone’s data connection was laggy in a more consistent way than when I tried to use wifi in a busy cafe.

Regarding SIM cards in China, I have some tips to share as well. I ended up buying a prepaid China Unicom SIM with 2 GB of data from Amazon before I left for my trip, which was incredibly convenient. The way this works is you buy the SIM online, they send it to you, and you have to activate it over email with the seller. Once the SIM is activated, the 90-day lifetime of the SIM doesn’t start until you actually begin to use it, so you can complete the activation well before your trip and then pop the SIM card into your phone once you land in China. I have no complaints about dealing with the seller LvyCom on Amazon and would definitely recommend them.

So how was ExpressVPN? Decent and reliable, but not especially fast. I found it helped significantly to change the connection type from “auto” to “udp”, but Astrill’s Openweb connection type still beat it when it came to speeds. But to set expectations – generally the speeds were still slow. My friend had an 80 Mbit home internet connection which I tested without the VPN enabled, but once I enabled a VPN, the best I could get from it was around 3-5 Mbit. This was generally only good enough to watch YouTube videos at 480p. My friend was quite surprised when I told him I always watch YouTube at home at 1080p resolution with no hiccups or delays.

Shadowsocks turned out to be the least reliable method of tunneling out of China, sometimes working well and sometimes not working at all. Since it’s a lot of extra effort to set up a Shadowsocks server compared to just using a commercial VPN, I don’t think it’s necessary unless you want to have that extra peace of mind.

Overall I was able to get work done while in China, but it was regularly a frustrating experience to deal with the lack of bandwidth and annoying latency on SSH terminal sessions. Oh, and bring good headphones if you plan to try to work from coffee shops!

Photos from my recent trip to Beijing can be found here. For news about the GFW and VPNs, I recommend greatfire.org.

This video sums up one of my favorite reasons for being alive: