Category: Software

Workaround/solution for Audio crash/hang loud beep after a certain period – rt5650 on HP Chromebook G5

By , 2023-01-09 19:16

Installing Ubuntu 22.04 or Linux Mint on an HP Chromebook G5 EE works fine, except for the audio hanging and producing a loud beep until pulseaudio is restarted. The solution :

On 12/18/22 7:02 AM, Mark Hills wrote:
HP Chromebook (11a, G5 “Setzer”) uses snd_soc_sst_cht_bsw_rt5645 module
and presents a device “rt5650”.

can you share the result of ‘aplay -l’, wondering which platform driver you are using.
Audio works briefly, until after about 30 seconds it’s interrupted by a
square wave or short buffer cycling.

If this is with the SOF driver, there’s a known issue and a known workaround, please add this to /etc/modprobe.d/alsa-base.conf

options snd_sof sof_debug=1
— Read on

NVIDIA GPU ‘passthrough’ to lxc containers on Proxmox 6 for NVENC in Plex

By , 2020-12-06 20:19

I’ve found multiple guides on how to enable NVIDIA GPU access from lxc containers, however I had to combine the information from multiple sources to get a fully working setup. Here are the steps that worked for me.

  1. Install dkms on your Proxmox host to ensure the nvidia driver can be auto-updated with new kernel versions.
    # apt install dkms
  2. Head over to and get the latest supported Nvidia binary driver version listed there.
  3. Download the nvidia-patch repo
    git clone
  4. Install the driver from step 2 on the host.
    For example, ./
  5. Run the nvidia-patch/ script on the host.
  6. Install the same driver in each container that needs access to the Nvidia GPU, but without the kernel module.
    ./ --no-kernel-module
  7. Run the nvidia-patch/ script on the lxc container.
  8. On the host, create a script to initialize the nvidia-uvm devices. Normally these are created on the fly when a program such as ffmpeg calls upon the GPU, but since we need to pass the device nodes through to the containers, they must exist before the containers are started.

    I saved the following script as /usr/local/bin/nvidia-uvm-init. Make sure to chmod +x !
## Script to initialize nvidia device nodes.
/sbin/modprobe nvidia
if [ "$?" -eq 0 ]; then
  # Count the number of NVIDIA controllers found.
  NVDEVS=`lspci | grep -i NVIDIA`
  N3D=`echo "$NVDEVS" | grep "3D controller" | wc -l`
  NVGA=`echo "$NVDEVS" | grep "VGA compatible controller" | wc -l`
  N=`expr $N3D + $NVGA - 1`
  for i in `seq 0 $N`; do
    mknod -m 666 /dev/nvidia$i c 195 $i
  mknod -m 666 /dev/nvidiactl c 195 255
  exit 1
/sbin/modprobe nvidia-uvm
if [ "$?" -eq 0 ]; then
  # Find out the major device number used by the nvidia-uvm driver
  D=`grep nvidia-uvm /proc/devices | awk '{print $1}'`
  mknod -m 666 /dev/nvidia-uvm c $D 0
  mknod -m 666 /dev/nvidia-uvm-tools c $D 0
  exit 1

Next, we create the following two systemd service files to start this script, and the nvidia-persistenced:


# nvidia-uvm-init.service
# loads nvidia-uvm module and creates /dev/nvidia-uvm device nodes
Description=Runs /usr/local/bin/nvidia-uvm-init


# NVIDIA Persistence Daemon Init Script
# Copyright (c) 2013 NVIDIA Corporation
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# This is a sample systemd service file, designed to show how the NVIDIA
# Persistence Daemon can be started.
Description=NVIDIA Persistence Daemon
ExecStart=/usr/bin/nvidia-persistenced --user nvidia-persistenced
ExecStopPost=/bin/rm -rf /var/run/nvidia-persistenced

Next, symlink the two service definition files into /etc/systemd/system

# cd /etc/systemd/system
# ln -s /usr/local/lib/systemd/system/nvidia-uvm-init.service
# ln -s /usr/local/lib/systemd/system/nvidia-persistenced.service

and load the services

# systemctl daemon-reload
# systemctl start nvidia-uvm-init.service
# systemctl start nvidia-persistenced.service

Now you should see all the nvidia device nodes have been created
# ls -l /dev/nvidia*
crw-rw-rw- 1 root root 195, 0 Dec 6 18:07 /dev/nvidia0
crw-rw-rw- 1 root root 195, 1 Dec 6 18:10 /dev/nvidia1
crw-rw-rw- 1 root root 195, 255 Dec 6 18:07 /dev/nvidiactl
crw-rw-rw- 1 root root 195, 254 Dec 6 18:12 /dev/nvidia-modeset
crw-rw-rw- 1 root root 511, 0 Dec 6 19:00 /dev/nvidia-uvm
crw-rw-rw- 1 root root 511, 0 Dec 6 19:00 /dev/nvidia-uvm-tools

total 0
cr-------- 1 root root 236, 1 Dec 6 18:07 nvidia-cap1
cr--r--r-- 1 root root 236, 2 Dec 6 18:07 nvidia-cap2

Check the dri devices as well
# ls -l /dev/dri*
total 0
drwxr-xr-x 2 root root 100 Dec 6 17:00 by-path
crw-rw---- 1 root video 226, 0 Dec 6 17:00 card0
crw-rw---- 1 root video 226, 1 Dec 6 17:00 card1
crw-rw---- 1 root render 226, 128 Dec 6 17:00 renderD128

Take note of the first number of each device after the group name. In the listings above I have 195, 511, 236 and 226.

Now we need to edit the lxc container configuration file to pass through the devices. Shut down your container, then edit the config file – example /etc/pve/lxc/117.conf. The relevant lines are below the swap: 8192 line

arch: amd64
cores: 12
features: mount=cifs
hostname: plex
memory: 8192
net0: name=eth0,bridge=vmbr0,firewall=1,gw=,hwaddr=4A:50:52:00:00:00,ip=,type=veth
onboot: 1
ostype: debian
rootfs: local-lvm:vm-117-disk-0,size=250G,acl=1
startup: order=99
swap: 8192
lxc.cgroup.devices.allow: c 195:* rwm
lxc.cgroup.devices.allow: c 226:* rwm
lxc.cgroup.devices.allow: c 236:* rwm
lxc.cgroup.devices.allow: c 511:* rwm
lxc.mount.entry: /dev/dri dev/dri none bind,optional,create=dir
lxc.mount.entry: /dev/nvidia-caps dev/nvidia-caps none bind,optional,create=dir
lxc.mount.entry: /dev/nvidia0 dev/nvidia0 none bind,optional,create=file
lxc.mount.entry: /dev/nvidiactl dev/nvidiactl none bind,optional,create=file
lxc.mount.entry: /dev/nvidia-uvm dev/nvidia-uvm none bind,optional,create=file
lxc.mount.entry: /dev/nvidia-modeset dev/nvidia-modeset none bind,optional,create=file
lxc.mount.entry: /dev/nvidia-uvm-tools dev/nvidia-uvm-tools none bind,optional,create=file

Now, start your container back up. You should be able to use NVENC features. You can test by using ffmpeg:
$ ffmpeg -i dQw4w9WgXcQ.mp4 -c:v h264_nvenc -c:a copy /tmp/rickroll.mp4

You should now have working GPU transcode in your lxc container!

If you get the following error, recheck and make sure you have set the correct numeric values for lxc.cgroup.devices.allow and restart your container.

[h264_nvenc @ 0x559f2a536b40] Cannot init CUDA
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width
or height
Conversion failed!

Another way to tell the values are incorrect is having blank (———) permission lines for the nvidia device nodes. You will get this inside any containers that are started before the nvidia devices are initialized by the nvidia-uvm-init script on the host.

$ ls -l /dev/nvidia*
---------- 1 root root        0 Dec  6 18:04 /dev/nvidia0
crw-rw-rw- 1 root root 195, 255 Dec  6 19:02 /dev/nvidiactl
---------- 1 root root        0 Dec  6 18:04 /dev/nvidia-modeset
crw-rw-rw- 1 root root 511,   0 Dec  6 19:02 /dev/nvidia-uvm
crw-rw-rw- 1 root root 511,   1 Dec  6 19:02 /dev/nvidia-uvm-tools

Sometimes, after the host has been up for a long time, the /dev/nvidia-uvm or other device nodes may disappear. In this case, simply run the nvidia-uvm-init script, perhaps schedule it to run as a cron job.

Install OpenSSH Server on Windows 10

By , 2020-07-14 23:52

In an Administrator PowerShell session:

# Install the OpenSSH Server
Add-WindowsCapability -Online -Name OpenSSH.Server~~~~
# Set service to Automatic startup
Set-Service -Name sshd -StartupType 'Automatic'
# Start service
Start-Service sshd
# Confirm the Firewall rule is configured. It should be created automatically by setup. 
Get-NetFirewallRule -Name *ssh*

pulseaudio-dlna + Yamaha AV Receiver RX-V573

By , 2018-09-03 15:52

It “just works!”

Install pulseaudio-dlna from Ubuntu default repos, then run pulseaudio-dlna. The first time, it failed, but I think that’s because the receiver was switched off. Console output did show it had been detected though. After switching on the receiver then running pulseaudio-dlna again, it redirected my currently playing audio to the receiver after a few seconds! So far this is the first time I’ve managed to get DLNA live streaming working with this receiver in 5 years of owning it.

Cheap, portable Linux laptop – Acer C720 Chromebook

By , 2018-09-03 15:08

Note: this post is more intended for personal reference; as such the quality of writing is not up to my standard, but I’ve decided to publish it as-is anyway since I don’t have time to review and figure it could be useful to someone.

I was looking for a good portable Linux laptop to that I could carry around without being too worried about battery life or the device getting scratched up in my bag. I tried a few different devices, including the HP Folio 13, ThinkPad X131e, GPD Pocket, Dell Latitude E7240. Finally I settled on the Acer C720 Chromebook. The main points in favour of this device are, for me:

  • Compact, thin and light (11.6″)
  • Relatively low cost (4GB RAM model can be had for under $150 CAD)
  • Proper modern low-voltage Intel Core processor (Celeron 2957U – Haswell) and not an Atom core or high-end i7
  • Dual-band Wi-Fi and Bluetooth

and the main downsides:

  • Basic TN LCD panel
  • 16GB storage
  • Runs Chrome OS
  • Chrome OS keyboard layout

The good news is the downsides are fairly easily remedied.

TN LCD Panel

The Acer C720 uses a standard 11.6″ LED backlit eDP panel. I was able to find an IPS panel to replace it on (model N116BCA-EA1). The panel replacement is fairly straightforward; care needs to be taken not to break the LCD bezel or any of the clips.


The SSD on the C720 is a standard M.2 2242 SATA SSD. The M.2 slot is easily accessible after removing the Chromebook’s bottom cover.

Runs Chrome OS

The Chrome OS/Linux dual-boot process is done by using the chrx script ( Remember to remove the write-protect screw while the bottom cover is off.

Chrome OS keyboard layout

This was arguably the hardest part. I chose to run Xubuntu, so the steps I went through apply to that environment. Chrx by default provides good defaults, mapping the back, forward, refresh, brightness and volume keys. The big issue for me was the placement of the power button (above the backspace key)

  1. Prevent systemd-logind from handling the power button
    edit /etc/systemd/logind.conf and add the following line:
  2. Prevent xfce power manager from handling the power button
    xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/logind-handle-power-key -s true
  3. Allow xfce power manager to handle lid switch
    xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/logind-handle-lid-switch -s false
  4. Remap power key to Delete
    xmodmap -e “keycode 124 = Delete”
    To find the keycode, stop lightdm, startx to start a basic X session, then use xev to get the keycode for the power key.


Other tweaks

Consistent custom wallpaper/background for boot splash, login, and lock screen

  • gnome-screensaver uses the Gnome DE’s wallaper setting. Configure this via CLI:
    gsettings set org.gnome.desktop.background picture-uri file:///usr/local/share/wallpaper/animevillage.jpg
  • lightdm-gtk-greeter can be configured using GUI tool lightdm-gtk-greeter-settings or by editing /etc/lightdm/lightdm-gtk-greeter.conf
  • plymouth/boot splash:
    • go to /usr/share/plymouth/themes and create a copy of the xubuntu-logo directory. I called mine xubuntu-logo-mod
      sudo cp -R xubuntu-logo xubuntu-logo-mod
    • within the new xubuntu-logo-mod directory, rename and edit config files accordingly
      325 cd xubuntu-logo-mod/
      326 ls
      327 sudo mv xubuntu-logo.plymouth xubuntu-logo-mod.plymouth
      328 sudo mv xubuntu-logo.script xubuntu-logo-mod.script
      329 sudo nano xubuntu-logo-mod.script
    • replace wallpaper.png in xubuntu-logo-mod directory with desired image. I used ImageMagick’s convert tool to convert my jpg format image to png.
    • add new theme we have created as an “alternative” with higher priority
      • Find out priority and config for current theme
        sudo update-alternatives –query default.plymouth
        Name: default.plymouth
        Link: /usr/share/plymouth/themes/default.plymouth
        Status: auto
        Best: /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth
        Value: /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth

        Alternative: /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth
        Priority: 200

        Alternative: /usr/share/plymouth/themes/xubuntu-logo/xubuntu-logo.plymouth
        Priority: 150

      • Create new alternative with higher priority
        sudo update-alternatives –install /usr/share/plymouth/themes/default.plymouth default.plymouth /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth 200




Getting LightDM/sddm to use a custom screen layout (Kubuntu/Xubuntu 18.04 – xorg)

By , 2018-04-23 12:55
    1. Adjust screen layout using your DE’s tool.
    2. Install and run arandr. arandr will read the current display layout and allow you to save it as an xrandr script.
    3. Place the script from arandr somewhere safe (I put it in /usr/local/bin).
    4. Create file /etc/lightdm/lightdm.conf.d/displays.conf with the following content:

      Where “/usr/local/bin/” is the path to the script saved from arandr.
      For sddm, instead edit /usr/share/sddm/scripts/ and add a line to have it run the same “/usr/local/bin/” script.

      # Xsetup - run as root before the login dialog appears
      # set screen layout using Xrandr
    5. Restart lightdm or sddm
      sudo systemctl restart lightdm.service
      sudo systemctl restart sddm.service


Enabling MD5withRSA in newer versions of Java

By , 2018-04-08 10:28

Oracle have decided to disable access to Java apps that use MD5withRSA signatures. For instance, when launching the .jnlp file to connect to my Lantronix Spider remote KVM, I am presented with this error:

To fix this, we have to change Java’s security settings. Unfortunately, settings for signature algorithms are not in the Java Control Panel, so we have to edit the config files directly.

On macOS, the default JRE installation’s root directory ($JAVA_HOME) is

/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home

on Windows, it would be

C:\Program Files\Java\jre1.8.0_131

where “1.8.0_131” is your specific Java version, and on Linux, JRE is installed in


once again where “1.7.0-openjdk-amd64” is your specific Java version.

In the JRE directory, we then need to edit the file


and comment out the line that starts with “jdk.jar.disabledAlgorithms” by prefixing a #. Note that this will allow jar files signed with any algorithms to run, which can be considered insecure.



3CX Debian PBX behind pfSense Firewall

By , 2017-10-21 22:18

Quick notes on some tweaks I had to do to get 3CX’s Firewall Check to pass behind my home pfSense firewall:

  • Allow PBX to access Google DNS ( It seems like 3CX is hardcoded to use at the license validation stage. I had blocked on my end to prevent Android and Chromecast devices from preferring external DNS over my local DNS server and this caused the error License_Error httpsError in 3CX.
  • Create DHCP-Static mapping for 3CX server.
  • Configure NAT Port-forwarding rules: I used the list at for reference. Table reproduced below.


    Port (Default)


    Port Forwarding Required


    5001 or 443

    v15: HTTPs port of Web Server. This port can be configured.

    Yes – if you intend on using a 3CX client, Bridge Presence, Remote IP Phones from outside your LAN and 3CX WebMeeting functionality.



    V15: This port is used for the online Web-Based installer wizard (NOT 3CX config command line tool) only during the installation process.

    Optional – During the installation process when the Web-Based installer is used from external source

    UDP & TCP


    3CX Phone System (SIP)

    Yes – if you intend on using VoIP Providers, WebRTC and Remote Extensions that are NOT using the 3CX Tunnel Protocol



    3CX Phone System (SecureSIP) TLS

    Yes – if you intend on using Secure SIP remote extensions

    UDP & TCP


    3CX Tunnel Protocol Service Listener

    Yes -if you intend on using remote extensions using the 3CX Tunnel Protocol (within the 3CX clients for Windows / Android / iOS) or when using the 3CX Session Border Controller


    9000-9500 (default)

    3CX Media Server (RTP) – WAN audio/video/t38 streams

    Yes – if you intend on using remote extensions or a VoIP Provider

  • Configure Outbound NAT Static rule for 3CX server: Automatic Outbound NAT (Default pfSense config) causes a random source port to be used for requests outbound to the Internet. 3CX doesn’t like this behaviour, so we need to add an Advanced Outbound NAT rule to force traffic coming from the 3CX server to use “Static Port” translation, as seen in the following screenshot. For Source, select “Network” and use the 3CX server IP with a mask of /32 (single host).

After completing these steps, the 3CX Firewall Check passes all green.

Collection of Firefox add-ons

By , 2017-06-04 14:58

Finally got around to making a collection of all the Firefox add-ons I use. The collection has been refined over the past 10 years or so and everything in this collection is compatible with Multiprocess (e10s).

These addons are part of the reason I still prefer using Firefox. Privacy concerns aside, Chrome just isn’t that customizable – Chrome add-ons just aren’t as useful in my everyday browsing.

Copy mailbox contents to new mailbox – Office 365

By , 2017-04-13 12:09

First, connect to Exchange Online PowerShell

$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session

Then, use the Search-Mailbox cmdlet

Search-Mailbox -Identity "MAILBOX1" -TargetMailbox "MAILBOX2" -TargetFolder "Moved From Old Mailbox" -LogLevel Full



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