Recently I decided to run exclusively FreeBSD 11.2 (RC3) on my new Thinkpad T480. I'm using drm-kmod-next, overall the system runs quite well. But one really annoying problem is that none of the FN-brightness up/down, wireless, etc.. was working. Even using the acpi_ibm driver. It took me a whole week-end, but at the end I found that the acpi_ibm driver does not support new Thinkpad Models. I've worked out a patch to enable support for newer models, the patch is submitted here https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229120. It works perfectly fine for my T480, my I'm pretty sure it will work also for other models.
I hope the patch will be useful for somebody here, if you have a new Thinkpad model you can try it out, but the above patch applies on top of another one that has been already pushed to 12-CURRENT, https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229074. This one adds *dev.acpi_ibm.0.mic_led* sysctl to turn on/off the led light over mic mute (F4) button, found on some models (like my x230 and T480).
I hope the patch will be useful for somebody here, if you have a new Thinkpad model you can try it out, but the above patch applies on top of another one that has been already pushed to 12-CURRENT, https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229074. This one adds *dev.acpi_ibm.0.mic_led* sysctl to turn on/off the led light over mic mute (F4) button, found on some models (like my x230 and T480).