Comment 150 for bug 1791427

@ALinuxUser: the patches are not yet upstream and thus one has to build a patched kernel yourself. You can follow the upstream process in the links posted from aaronma.

For some people it is working because they have a different touchpad. But according to the above discussion even the patches probably wont work for you :/

at your own risk!!!
For building a kernel you first have to install all dependencies, should be the following:
    apt-get install build-essential git wget kernel-package fakeroot dpkg-dev \
                libncurses5-dev libssl-dev ccache flex bison libelf-dev tzdata

then you need to git clone the kernel source:
    git clone --depth 1 --branch v5.0.1 git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

get the patches
    wget -O first.patch https://lkml.org/lkml/diff/2019/2/20/700/1
    wget -O second.patch https://lkml.org/lkml/diff/2019/2/20/701/1

apply the patches
    cd linux
    git apply ../first.patch
    git apply ../second.patch

clean the repo (just in case)
    make clean && make mrproper

copy the config of your current kernel
    sudo cp /boot/config-`uname -r` .

adjust the config
    yes '' | make oldconfig

and now compile it, can take a while
    make deb-pkg

at your own risk! you can then install the generated deb files