Ubuntu isn't booting after overclock and config.txt is getting automatically altered

I did an overclock on ubuntu 21.04 on my raspberry pi 4b 8gb ram. I went to arm_freq=2100 and gpu_freq=750 and over_volt 6; that worked fine. I tried arm_freq=2200 and gpu_freq=800 with the same overvolt and it did not boot. I turned it back down to the first overclock and even tried turning the overclock off altogether, or back to stock settings and it did not boot. What's wrong? And what can be done about it? The thing is the config.txt changes without me editing it like so. It seems like the computer does it. Here is how it should be (stock settings)

[pi4]
max_framebuffers=2
[all]
kernel=vmlinuz
cmdline=cmdline.txt
initramfs initrd.img followkernel
# Enable the audio output, I2C and SPI interfaces on the GPIO header
dtparam=audio=on
dtparam=i2c_arm=on
dtparam=spi=on
# Enable the KMS ("full" KMS) graphics overlay, and allocate 128Mb to the GPU
# memory. The full KMS overlay is required for X11 application support under
# wayland
dtoverlay=vc4-kms-v3d
gpu_mem=208
# Uncomment the following to enable the Raspberry Pi camera module firmware.
# Be warned that there *may* be incompatibilities with the "full" KMS overlay
#start_x=1
# Comment out the following line if the edges of the desktop appear outside
# the edges of your display
disable_overscan=1
# If you have issues with audio, you may try uncommenting the following line
# which forces the HDMI output into HDMI mode instead of DVI (which doesn't
# support audio output)
#hdmi_drive=2
# If you have a CM4, uncomment the following line to enable the USB2 outputs
# on the IO board (assuming your CM4 is plugged into such a board)
#dtoverlay=dwc2,dr_mode=host
# Config settings specific to arm64
arm_64bit=1
dtoverlay=dwc2

This is how it actually is. As you can see, the config.txt gets altered automatically.

max_framebuffers=2
kernel=vmlinuz
cmdline=cmdline.txt
initramfs initrd.img followkernel
# Enable the audio output, I2C and SPI interfaces on the GPIO header
dtparam=audio=on
dtparam=i2c_arm=on
dtparam=spi=on
# Enable the KMS ("full" KMS) graphics overlay, and allocate 128Mb to the GPU
# memory. The full KMS overlay is required for X11 application support under
# wayland
dtoverlay=vc4-kms-v3d
gpu_mem=208
# Uncomment the following to enable the Raspberry Pi camera module firmware.
# Be warned that there *may* be incompatibilities with the "full" KMS overlay
#start_x=1
# Comment out the following line if the edges of the desktop appear outside
# the edges of your display
disable_overscan=1
# If you have issues with audio, you may try uncommenting the following line
# which forces the HDMI output into HDMI mode instead of DVI (which doesn't
# support audio output)
#hdmi_drive=2
# If you have a CM4, uncomment the following line to enable the USB2 outputs
# on the IO board (assuming your CM4 is plugged into such a board)
#dtoverlay=dwc2,dr_mode=host
# Config settings specific to arm64
arm_64bit=1
dtoverlay=dwc2

I tried adding the [pi 4] and the [all] lines and it still does not boot. It seems most puzzeling and I can't make it out at all.

1 Answer

I had a similar problem, although different as I was able to regain my system when removing the overclock settings. Also I was able to log into the tty sessions (it took several attempts with shift-ctrl-f2 - f4 + <return> to be able to access a session), the GUI did not display, though the processes all seemed to be running alright - I did not check system logs.

With Ubuntu 21.10 on a Pi4B 8GB RAM, I was able to overclock the CPU, but not the GPU (yet) - seems like wayland did not like the parameter change.

You may try to re-instal a fresh system (just in case the X/Wayland configuration got corrupted), then try the overclock without the GPU setting.