I am running my raspberry pi 3 with a radio station software PiFmRds The program works fine but then when I go to move the window (or any other window) the system freezes and I have to unplug and replug my pi in.

Where can I find the appropriate error log to narrow down the problem?

I have a webserver on the same pi and after it freezes it is still serving my web pages (I have checked the cache)

If it helps, I use VNC

My pi working BEFORE i move a window

  • Are you using the latest fully updated Rasbpian Stretch ? What spec power supply are you using ?
    – CoderMike
    Commented Nov 1, 2017 at 17:37
  • @CoderMike I am using the official desktop kit. Heres the power supply: amazon.co.uk/dp/B01CI58722/…
    – cobra12
    Commented Nov 1, 2017 at 17:43
  • @CoderMike. I am using rasbian jessie. as /etc/os-releases/ outputs.
    – cobra12
    Commented Nov 1, 2017 at 17:45

3 Answers 3


I used to have the same issue. After i updated to debian stretch it works most part. Every once in a while itll freze but it works niw for me so update to stretch by using:


  • Remove unnecessary or obsolete packages
  • Make a data and configuration backup
  • Perform an upgrade directly using console Installed 3rd-party software on Raspbian Stretch 9

Important Note:

MariaDB is now the default SQL database in Debian 9 Stretch. This introduces a new database binary data file format which is not backwards compatible with your current ( Debian 8 Jessie ) database format. During the upgrade your databases will be upgraded automatically. However, when you run into some issues during or after the upgrade, you will not be able revert back! From this reason it is important to backup all your current databases before you proceed with a Debian 9 Stretch upgrade!

REFERENCE: debian.org

Now lets begin to update you: Start by fully upgrade your current Raspbian system before you proceed with a Stretch upgrade.

sudo bash
apt-get update
apt-get upgrade
apt-get dist-upgrade

Last, chance to check for any system inconsistencies. Perform database sanity and consistency checks for partially installed, missing and obsolete packages:

dpkg -C

If no issues are reported, check what packages are held back:

apt-mark showhold

Packages On Hold will not upgrade. On Hold packages may cause inconsistencies after Stretch upgrade. Before you move to the following part, it is suggested to fix all issues provided by both above commands.

Next, update your /etc/apt/sources.list to include new Stretch repositories.

sed -i 's/jessie/stretch/g' /etc/apt/sources.list

The above command will replace any Jessie keyword occurrence to Stretch thus effectively enabling new Stretch repositories. Once your /etc/apt/sources.list is updated to included Stretch repositories, update your local package index with:

apt-get update

Use the below command to see what we are facing. It is a simulated dry-run thus not system changes will be implemented.

apt-get --simulate upgrade

We have come to the most exciting part, which is the actual Jessie upgrade to Raspbian Stretch system. During the upgrade you may be asked:

There are services installed on your system which need to be restarted when certain libraries, such as libpam, libc, and libssl, are upgraded. Since these restarts may cause interruptions of service for the system, you will normally be prompted on each upgrade for the list of services you wish to restart. You can choose this option to avoid being prompted; instead, all necessary restarts will be done for you automatically so you can avoid being asked questions on each library upgrade.

Restart services during package upgrades without asking? The choice is about whether you wish the system to restart your services automatically during the system upgrade or you wish to do it manually or after the system is fully upgrade to Stretch. When ready, execute the bellow commands to commence the Debian Stretch upgrade process:

apt-get upgrade
apt-get dist-upgrade

All done. Reboot your system with:

  • 1
    Ah thanks so much I have updated but forgot to simulate first. sure it will e okay since its new and I havnt done too much with it it doesnt matter if i loose it. Il let you know how I got on when its complete.
    – cobra12
    Commented Nov 1, 2017 at 19:02
  • 1
    Yeah i have but sorry i cant upvote because i dont have enough reputation.
    – cobra12
    Commented Nov 1, 2017 at 19:16
  • 1
    @User98764432 thats ok I dont know if I will need to use the database on my new pi il keep it on the pi 2.
    – cobra12
    Commented Nov 1, 2017 at 19:17
  • ok, didnt know , since you said a server is run on it, didnt know if it was using a database Commented Nov 1, 2017 at 19:20
  • My system still freezes when i move the window!
    – cobra12
    Commented Nov 2, 2017 at 15:44

The real problem: It was a software issue.

The PiFmRds Modulator uses DMA Engine 0 - which worked fine on my Pi2 but on the Raspberry Pi 3 It is used for framebuffering, which explains the freezing.

Simply setting the software to use DMA engine 5 may work, but I was having problems with the transmission cutting out after ~10 seconds. I am now using DMA Engine 6 (which is supposedly used by GPU) But I haven'tavnt noticed anything and it works fine!

Bassically apply this commit: https://github.com/SaucySoliton/PiFmRds/commit/fcfccdd0fe06c556f9b4e5776b516c1b9f5f2093


Bassically apply this commit: https://github.com/SaucySoliton/PiFmRds/commit/fcfccdd0fe06c556f9b4e5776b516c1b9f5f2093

How did you applied the commit?

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