The other day I replaced the touchpad in my Lenovo ThinkPad T440 laptop with a touchpad for T450, read more about it here.

The T450 touchpad’s buttons did not work as expected and required a workaround to function. However, applying that workaround had the downside with multi-finger gestures, such as two-finger scroll, not working.

Luckily this has been fixed in Linux kernel 4.0.0-rc5, which was just released. rc stands for release candidate, so it might not be such a good idea to run it in a critical environment. With kernel 4.0 you do not need any workaround anymore, and the touchpad and its buttons work just as expected.

On apps.fedoraproject.org/packages/kernel I saw that the latest rc was available in Rawhide, which is Fedora’s rolling testing version. Then I went over to ask.fedoraproject.org and got to know that the kernel in Rawhide can be installed on regular stable Fedora by performing these three steps:

$ cd /etc/yum.repos.d
$ sudo wget http://alt.fedoraproject.org/pub/alt/rawhide-kernel-nodebug/fedora-rawhide-kernel-nodebug.repo
$ sudo dnf upgrade

This will add a repository containing the Rawhide kernel and then upgrade the system. After a reboot it will be working. However, if you have applied any workarounds, such as the GRUB parameters, you probably want to remove them.

The current latest kernel version in stable Fedora is 3.19.1, which suffers from the touchpad problem. So I will continue to run Rawhide’s kernel until 4.0 has gone stable and reached stable Fedora, then I will switch back. But this works great in the meantime.