System fail to boot with Ubuntu 16.04

[David Chen]

Skylake systems fail to boot with Ubuntu 16.04
CPU: Intel i5-6440EQ, i7-6820EQ
Kernel version: 4.4.0-8
Mainline kernel tested fail: 4.3.x, 4.4.x, 4.5.x
Mainline kernel tested pass: In progress....

Reproduce steps:
1. Boot from the bootable USB drive (in UEFI mode)
2. Select "Install Ubuntu" from the boot menu

Expected Behavior:
System completes installation successfully.

Actual Behavior:
Blank screen right after the grub option is made.

[Timo Aaltonen (tjaalton)]

fyi: this is not related to i915 graphics, since 4.1.x didn't support skylake, 4.3 and up does.

[Chih-Hsyuan Ho (chih)]

With Ubuntu 16.04 daily build (2/25) and kernel: 4.4.0-7-generic #22 , tried the following kernel options:

1) acpi=off => OK
2) intel_pstate=disable => Fail to boot
3) intel_idle.max_cstate=0 => OK
4) iommu=off => Fail to boot

[Timo Aaltonen (tjaalton)]

what does 'lspci -nv|grep VGA' give?

[Timo Aaltonen (tjaalton)]

nevermind about #3, I was mixing this with something else..

[Len Brown (len-brown)]

The intel_idle.max_cstate=0 issue should be fixed in 4.6-rc1,
as documented in the upstream bug report:

https://bugzilla.kernel.org/show_bug.cgi?id=109081