Created attachment 187971 [details] dmesg output On my system the kernel prints a stack trace and some error messages on every boot, see below. This is currently not causing any notable malfunction, but I wonder what this is about. I tried bisecting the issue and endet up with this commit as the first bad commit: 15c1247953e8a45232ed5a5540f291d2d0a77665 Interestingly that's itself a revert of a previous commit. The device is a Thinkpad X1 Carbon 2014 edition (20A7). I'll attach the dmesg output. Here's some more info about the hw, like lspci, dmidecode, lsusb output: http://int21.de/x1carbon/data/ (I had previously reported this to the kernel mailing list, but got no reactions)