This was a way to return to the old Raspberry Pi kernel 4.19 for Raspberry Pi users from over three weeks ago. I don't believe you would be using this with Ubuntu. There have been a number of further tweaks to kernel 5.4 from RPi.org since then which for me have solved this problem. My ASI cameras are all operating properly now. One issue which has been reported elsewhere continues - it seems that USB serial interface adapter devices from FTDI don't work consistemtly. Typical products that suffer as a consequence are SW mount EQMOD EQDirect cables wuth FTDI chips, and my Pegasus Astro Pocket Power Box which includes an FDTI brand chip.But again this is in the RPi implementations.
rishigarrod wrote: Jasem posted this on the first page of this thread:
sudo rpi-update e1050e94821a70b2e4c72b318d6c6c968552e9a2
Worked perfectly for me.
sudo apt-get update && sudo apt-get -y dist-upgrade
SUBSYSTEM=="bcm2835-gpiomem", KERNEL=="gpiomem", GROUP="dialout", MODE="0660" SUBSYSTEM=="gpio", KERNEL=="gpiochip*", ACTION=="add", PROGRAM="/bin/sh -c 'chown root:dialout /sys/class/gpio/export /sys/class/gpio/unexport ; chmod 220 /sys/class/gpio/export /sys/class/gpio/unexport'" SUBSYSTEM=="gpio", KERNEL=="gpio*", ACTION=="add", PROGRAM="/bin/sh -c 'chown root:dialout /sys/%p/active_low /sys/%p/direction /sys/%p/edge /sys/%p/value ; chmod 660 /sys/%p/active_low /sys/%p/direction /sys/%p/edge /sys/%p/value'"