thinkpad-yoga-3rd-gen-acpi

An attempt to patch the ACPI for the ThinkPad X1 Yoga, 3rd Generation laptop, following this gist put together by @javanna.

My environment is Ubuntu 16.04 (xenial), running the latest HWE kernel from Ubuntu 18.04, which presently is 4.15.0-38-generic.

Steps

First obtain and compile a recent iasl. This is mandatory. It straight up won't work otherwise. To do this, you'll likely need to install a bunch of packages: build-essential, m4, bison, flex, and some other packages. Compile with make. If it fails, read the error messages and try to find packages that provide the utilities it's lacking.

Next, boot into at least Ubuntu 18.04 on a live CD/USB. I'm not sure if this is necessary, but I'll explain in more detail below.

Having compiled a recent iasl and having a runtime in Ubuntu 18.04, and assuming this iasl binary lives at bin/iasl, dump the ACPI DSDT table from the hardware:

cat /sys/firmware/acpi/tables/DSDT > dsdt.aml

Next, decompile the table into Assembly using iasl:

bin/iasl -d dsdt.aml

Download the patch:

wget http://kernel.dk/acpi.patch

Apply the patch:

patch --verbose < acpi.patch

There will be 1-2 conflicts. View the *.rej file to see the patches that failed and manually apply them.

After fixing the patching, compile back into bytecode:

bin/iasl -ve -tc dsdt.dsl

Let's create a CPIO archive containing our new ACPI DSDT table:

mkdir -p kernel/firmware/acpi
cp dsdt.aml kernel/firmware/acpi
find kernel | cpio -H newc --create > acpi_override

Create a directory to hold the override file:

mkdir -p /lib/acpi
cp acpi_override /lib/acpi

Install the initramfs hook provided here to bake the changes into the initramfs:

cp etc/initramfs-tools/hooks/acpi-override /etc/initramfs-tools/hooks/

To make sure that you don't get into an unable-to-boot state, make a backup of your current bootable initramfs and friends:

find /boot -iname "*$(uname -r)*" -exec cp {} {}-safe \;

Bake the initramfs and reboot into it:

update-initramfs -k all -c

The above command rebakes all kernels currently installed. You can update only the current kernel via update-initramfs -u -k $(uname -r).

After this, reboot into the new kernel and observe that it all works 🎉

$ dmesg | grep ACPI | grep supports
ACPI: (supports S0 S3 S4 S5)
$ cat /sys/power/mem_sleep
s2idle [deep]

Praise the Sun! It works! 🙌 🌞

This also fixed a resume bug for me which broke all of my pointer inputs on the laptop like the touchscreen, the Wacom pointer, the trackpoint, and the track pad.

License

Licensed at your discretion under either:

vozhyk-/thinkpad-yoga-3rd-gen-acpi

thinkpad-yoga-3rd-gen-acpi

Steps

License