Instead of restarting to recover wifi, try unpluging from power and suspend and wake again.
However, my touchscreen doesn't come back after sleep and the above didn't help at all.
I just got my XPS 9350 a couple of days ago and nothing else resolved GPU hangs except i915.enable_rc6=0.
I'm running Ubuntu 15.10 on Linux 4.5.
Just wanted to confirm the solution and say thank you.
I got my XPS 9350 yesterday and installed ubuntu-gnome-16.04-beta2. I changed
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.enable_rc6=0"
and hope this solve the video problem.
I've been using kernel 4.4.6 for the last few days (from Fedora 23) and so far it seems stable. No special boot parameters required.
i tried disabling rc6 when i got my xps about a week ago. it helped a bit but didnt fix completely.
for a complete fix this is what i did:
the archlinux page here wiki.archlinux.org/.../Dell_XPS_13_%282016%29
references this bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94161
there are two patches listed there which you need.
here is how to apply:
edit and uncomment all of the deb-src lines: sudo vi /etc/apt/sources.list
refresh apt: sudo apt-get update
get kernel sources: apt-get source linux-image-$(uname -r)
goto the i915_bpo driver used by 16.04: cd linux-4.4.0/ubuntu/i915
get first patch: curl -o patch.122643 https://bugs.freedesktop.org/attachment.cgi?id=122663
get second patch: curl -o patch.122644 https://bugs.freedesktop.org/attachment.cgi?id=122664
apply the patches:
patch -p5 < patch.122643
patch -p5 < patch.122644
now build driver (as normal user): make -C /lib/modules/`uname -r`/build M=$PWD modules
sudo cp -p i915_bpo.ko /lib/modules/4.4.0-16-generic/kernel/ubuntu/i915/i915_bpo.ko
reboot and you should be good to go. you can now remove the grub change you had done earlier in /etc/default/grub
run sudo update-grub and reboot again