Comment 17 for bug 1773232

How you do a bisect:

$ sudo apt build-dep linux
$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
$ cd linux
$ git bisect start
$ git bisect good v4.15-rc1
$ git bisect bad v4.15-rc2
$ make localmodconfig
$ make -j`nproc` deb-pkg
Install the newly built kernel, then reboot with it.

If the issue still happens,
$ git bisect bad
Otherwise,
$ git bisect good
Repeat to "make -j`nproc` deb-pkg" until you find the commit that causes the regression.