Hello, 

I'm exactly in the same problem. 

Since i updated the bios to 1.0.9, no linux want to start without the flag i915.modeset=0

Tested with installed manjaro, ubuntu installed and severals live cd.

Like you I tryed to downgrade the bios, by the windows bios setup, and by the bios recovery tool USB.
Nothing works, the bios version is stucked.

Can't use an external display or set the luminosity. When my Linux distribution goes to hibernation it's stucked on a blank screen.

There is a lots of forum post about "i915 and the black screen of death". I tested a lot of solutions, but nothing works.

This problem is very annoying. This laptop is one month old and I can't just use it a 100% of his capabilites.

Before the bios upgrade, i was very satisfied by this computer and linux where working like a charm. 

I would be happy to know a another method to downgrade the bios or communicate my serial number to get additionnal support. 

Is there Dell have a solution ?

Thanks.

I'm exactly in the same problem too. bios 1.1.9

Try this patch for recompiling the linux kernel

https://patchwork.freedesktop.org/patch/216371/

or

compile latest drm tip kernel.

This patch makes the Linux kernel booting.

Very good news ! Thanks to Dell for fixing.

I'm going to wait and watch for issues before applying this patch.

I have upgraded BIOS to ver. 1.2.3 and now nomodeset is not needed anymore, nor the kernel patch. Tested on debian and archlinux. Thank you Dell!

same  here  v1.2.3 Fixe 

There are no problem with it (3 days in use).