Ubuntu 19.10 has no working Keyboard or Mouse for Raspberry Pi 4 Model B, only works for Raspberry Pi 3 Model B+

Is there anyway to fix Ubuntu 19.10 for mouse & keyboard functionality on the Raspberry Pi 4 Model B? I can't even get the Ubuntu 19.10 login when the login pops up. I can only change the password when I switch to the Raspberry Pi 3 Model B+. The original image came from cdimage.ubuntu.com/releases/19.10/release/ubuntu-19.10-preinstalled-server-arm64+raspi3.img.xz from 64-bit for Raspberry Pi 3 and 4 link "Download the Ubuntu Server image" with website ubuntu.com/download/iot/raspberry-pi.

Solution 1:

If you don't want to wrangle patches or wait for them to be released, a workaround may be found in this thread, in one of leggazoid's posts of 10/20:

https://www.raspberrypi.org/forums/viewtopic.php?f=56&t=254649&sid=a82437abaa7e64ee930c7b4040eba764&start=25

Here's the good part, which worked on my 4GB Rpi 4 [edited for clarity]:

Set total_mem=3072 in /boot/firmware/usercfg.txt
(If you mount the sd card in another computer, the usercfg.txt is on the small vfat partition.)

Solution 2:

Ubuntu 19.10 arm64 on a Raspberry Pi 4 does not recognize a keyboard which works successfully on the same Raspberry Pi 4 with Ubuntu 19.10 armhf.

Setting total_mem=2048 in /boot/firmware/usercfg.txt allowed me to boot Pi4 4GB with 19.10 64bit with working USB. Of course I have less RAM now, but working USB.

Quoted from https://bugs.launchpad.net/ubuntu/+source/linux-raspi2/+bug/1848790

Earlier in launchpad report was

The USB-problem concerning the Raspberry Pi 4GB RAM model might be due to the issue seen earlier that using more RAM than 3072 MB breaks the USB: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=246766&start=25

The issue was solved by a kernel patch: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=246766&start=50#p1517839

and the kernel patch was this one: https://github.com/raspberrypi/linux/issues/3093#issuecomment-520269280

Your alternative is to use the armhf architecture.