PSA: The 5.17 kernel will require some initrd generator changes for kms drivers

Starting with kernel 5.17 the kernel supports the builtin privacy screens built into the LCD panel of some new laptop models.

This means that the drm drivers will now return -EPROBE_DEFER from their probe() method on models with a builtin privacy screen when the privacy screen provider driver has not been loaded yet.

To avoid any regressions distors should modify their initrd generation tools to include privacy screen provider drivers in the initrd (at least on systems with a privacy screen), before 5.17 kernels start showing up in their repos.

If this change is not made, then users using a graphical bootsplash (plymouth) will get an extra boot-delay of up to 8 seconds (DeviceTimeout in plymouthd.defaults) before plymouth will show and when using disk-encryption where the LUKS password is requested from the initrd, the system will fallback to text-mode after these 8 seconds.

I've written a patch with the necessary changes for dracut, which might be useful as an example for how to deal with this in other initrd generators, see: https://github.com/dracutdevs/dracut/pull/1666

I've also filed bugs for tracking this for Fedora, openSUSE, Arch, Debian and Ubuntu.