vc_dispmanx_display_open failed!

[misaacson01]

This error is sometimes seen during step 1 of operating the system. Whether you see this issue or not seems to depend on what monitor is plugged into the raspberry Pi: some HDMI monitors will cause this issue, others will not. If no HDMI monitor is plugged in (e.g. if you're remotely logged in to the Pi), you'll most likely run into this issue.

There are multiple potential solutions to this, so you might just have to try them one by one to see what works. The basic idea behind the fix is making sure that the HDMI display manager is running, which is required for the SPI display driver to work, but wont necessarily be running by default depending on what is plugged in to the Raspberry Pi.

1. Plug in an HDMI display, or change the resolution

   • If no HDMI display is plugged in to the Raspberry Pi, try plugging one in (or if you don't want to, proceed to solution 2)
   • If an HDMI display is plugged in, try changing the resolution
     • e.g. main menu > preferences > Raspberry Pi Configuration > Display > Set Resolution > 1024x768 60 Hz
   • Restart the Raspberry Pi and retry operating the system

2. Force HDMI display hotplugging

   • Open up the command terminal and type sudo nano /boot/config.txt
   • Scroll down until you see the line #hdmi_force_hotplug=1. Uncomment that line (delete the # symbol)
   • Hit ctrl-S to save the file, then exit the window
   • Restart the Raspberry Pi and retry operating the system

3. Try an older HDMI display driver

   • Open up the command terminal and type sudo nano /boot/config.txt
   • Scroll down until you see the line #dtoverlay=vc4-kms-v3d. Uncomment that line (delete the # symbol) and change kms to fkms
     • e.g. dtoverlay=vc4-fkms-v3d
   • Hit ctrl-S to save the file, then exit the window
   • Restart the Raspberry Pi and retry operating the system

This set of solutions seems to have solved all errors observed in MouseGoggles builds so far. If none work for you, post below! You may also want to check out this helpful discussion from the original display SPI driver repository, where much of the information on how to fix this issue came from.