Intel Skylake video: no output on VGA port
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-lts-xenial (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned |
Bug Description
Ubuntu release: 14.04.5 LTS
Kernel: linux-image-
I have a Dell Optiplex 7040 with an Intel Sky Lake r6 video card:
00:02.0 VGA compatible controller [0300]: Intel Corporation Sky Lake Integrated Graphics [8086:1912] (rev 06) (prog-if 00 [VGA controller])
Subsystem: Dell Device [1028:06b9]
Flags: bus master, fast devsel, latency 0, IRQ 128
Memory at f6000000 (64-bit, non-prefetchable) [size=16M]
Memory at e0000000 (64-bit, prefetchable) [size=256M]
I/O ports at f000 [size=64]
Expansion ROM at <unassigned> [disabled]
Kernel driver in use: i915_bpo
Running trusty with the lts-xenial kernel, I get no output on the built-in VGA port after grub has started the kernel. The monitor goes into power-save mode. The system does boot correctly and I can ssh into it. If I connect the monitor using one of the other ports (HDMI or DisplayPort) everything is visible.
When only the VGA port is connected to the monitor the kernel dmesg output contains:
[ 3.613697] i915_bpo 0000:00:02.0: DP-3: EDID block 0 invalid.
[ 3.614522] i915_bpo 0000:00:02.0: No connectors reported connected with modes
tags: | added: regression-update |
summary: |
- Optiplex 7040 - No output on VGA port + Intel Skylake video: no output on VGA port |
The problem only manifests itself when the monitor is attached through a KVM switcher.