ASUS UX305UA and Linux

The ASUS UX305UA is an ultrabook with the Skylake microarchitecture – the (as of writing) latest iteration in Intel processors. Unfortunately, Skylake support on Linux wasn’t really a granted thing the time the device got released. Fortunately it’s gotten a lot better of late.

After searching and reporting some bugs to the Debian Bugtracker, nearly everything works out of the box on Debian Sid (unstable), and probably soon on Stretch (current testing). So if you’re installing a new one now, I’d really suggest you go for Sid instead.

After installing the base system via a netinstall image, you’ll probably end up with a Stretch (testing) installation with a 4.3 kernel. This will not really work when rebooting, giving you a black screen. To solve that, boot with

i915.preliminary_hw_support=1 i915.modeset=0

on the kernel command line.

After this, I’d recommend adding a line for unstable and experimental to your apt sources:

# echo "deb http://httpredir.debian.org/debian/ unstable main contrib non-free" > /etc/apt/sources.list.d/unstable.list
# echo "deb http://httpredir.debian.org/debian/ experimental main contrib non-free" > /etc/apt/sources.list.d/experimental.list

and then upgrading your system to the latest unstable:
# apt-get update && apt-get dist-upgrade
This will result in you getting a linux-4.5 kernel and a boatload of updated drivers (eg. Xorg)

Next, upgrade even further: scary experimental mode on! This you’ll need to do manually (experimental never auto-upgrades, because of the possible breakage that might be caused):

First, find out the latest kernel

# apt-cache search linux-image-4 | grep amd64
linux-headers-4.5.0-1-amd64 - Header files for Linux 4.5.0-1-amd64
linux-image-4.5.0-1-amd64 - Linux 4.5 for 64-bit PCs
linux-image-4.5.0-1-amd64-dbg - Debugging symbols for Linux 4.5.0-1-amd64
linux-headers-4.6.0-rc3-amd64 - Header files for Linux 4.6.0-rc3-amd64
linux-image-4.6.0-rc3-amd64 - Linux 4.6-rc3 for 64-bit PCs
linux-image-4.6.0-rc3-amd64-dbg - Debugging symbols for Linux 4.6.0-rc3-amd64
linux-image-4.5.0-1-amd64-signed - Signatures for Linux 4.5.0-1-amd64 kernel and modules
linux-headers-4.4.0-1-grsec-amd64 - Header files for Linux 4.4.0-1-grsec-amd64
linux-image-4.4.0-1-grsec-amd64 - Linux 4.4 for 64-bit PCs, Grsecurity protection

As you can see above, 4.6.0-rc3 is available, but since it’s a prerelease kernel it’s not automatically installed. We want it, and with it, a bunch of firmware packages (to make sure we have the latest)
# apt-get install -t experimental linux-image-4.6.0-rc3-amd64 firmware-linux firmware-iwlwifi firmware-misc-nonfree intel-microcode
For good measure, you can even throw the latest iwlwifi firmware (not packaged yet in Debian) in the mix (found on GitHub):
# wget https://github.com/OpenELEC/iwlwifi-firmware/raw/master/firmware/iwlwifi-7265D-21.ucode -O /lib/firmware/iwlwifi-7265D-21.ucode
Next, reboot, and things should look a lot better already. Right now everything will work, except..

  • screen brightness buttons (Fn-F5 Fn-F6 Fn-F7). This requires (for now) this patch from kernel bugreport 98931. (Debian bugreport: 818494)
  • Screen auto brightness/ambient light (Fn-A): you can use the driver from GitHub
  • Disable-touchpad button (Fn-F7): you can use any old script, really. Just call synclient TouchpadOff=1 and it’s off. And =0 for on)