Since a few weeks I have the new ThinkPad X1 Carbon 6th Generation and as many people I really like it.
The biggest problem is that suspend does not work as expected.
The issue seems to be that the X1 is using a new suspend technology called "Windows Modern Standby," or S0i3, and has removed classic S3 sleep.[1]
Following the instructions in Alexander's article it was possible to get S3 suspend to work as expected and everything was perfect.
With the latest Firmware update to 0.1.28 (using sudo fwupdmgr update
(thanks a lot to Linux Vendor Firmware Service
(LVFS) that this works!!!)) I checked if the
patch mentioned in Alexander's article still applies and it did not.
So I modified the patch to apply again and made it available here: https://lisas.de/~adrian/X1C6_S3_DSDT_0_1_28.patch
Talking with Christian about it he mentioned an easier way to include the changed ACPI table into grub. For my Fedora system this looks like this:
cp dsdt.aml /boot/efi/EFI/fedora/
echo 'acpi $prefix/dsdt.aml' > /boot/efi/EFI/fedora/custom.cfg
Thanks to Alexander and Christian I can correctly suspend my X1 again.
Update 2018-09-09: Lenovo fixed the BIOS and everything described above is no longer necessary with version 0.1.30. Also see https://brauner.github.io/2018/09/08/thinkpad-6en-s3.html