Ubuntu on Dell XPS 13 (2015)
This site is inspired by ArchLinux Wiki Page and takes quite a few notes from it
A05 Update has solved all the issues including keyboard repeated typing problems. Put it in /boot/efi since that is also a FAT partition–or on a FAT formatted USB stick, reboot, hit f12, and select the option to update the firmware.
15.04 plays much more nicely than the default 14.04 on Developer Edition laptops.
4.3 rc kernels are working awesome with i915.enable_psr=1 . Idle usage ~ 2.7W. 4.2 was good but this gives a bump in the battery life. A minor caveat is that the pointer hangs and system freezes after a suspend sometimes. Tyring the solution here https://bbs.archlinux.org/viewtopic.php?id=198157 (uxa instead of sna). Let's see.
4.2 rc8 gives me an awesome battery life of > 11 hrs with the kernel options mentioned below. To install wifi drivers properly, you may have to install bcmwl-kernel-source from longsleep's ppa.
Otherwise, 4.1 kernels work okayish too, ~7-8 hrs of battery life. 4.1 kernels can be installed from Kernel PPA. The latest release is 4.1.4. With this release following options work the best: pcie_aspm=force i915.enable_fbc=1 i915.enable_rc6=7 i915.enable_psr=1
The i915.enable_psr=1 option causes flickering after a reboot for around 5-10 seconds but then it stops completely. The average discharge rate while normal browsing/coding is aroung 6-7W per hour (as opposed to 13W with kernel 3.19).
Touchpad does not detect palm and hence causes typing errors. The problem is only in 4+ kernels and not in 3.18~19 kernels. But kernel prior to 4.1 provide poor battery performance. libinput is the solution. You only have to change your synaptics.conf in /etc/X11/xorg.conf.d after installing libinput.
What will not work
Creating Wifi Hotspot (AP mode) in FHD versions
The drivers broadcom-wl do not support AP mode for the Broadcom chipset. The drivers that support it (brcmsmac) do not support the BCM4352 model which is present in most of the devices. Blame and shame Broadcom for not putting out proper drivers.