The setup
- T460 thinkpad (Intel HD Graphics) docked with lid closed connected to two external monitors one via DVI and the other via HDMI
The problem
- During boot, up until the login screen both monitors work fine. But as soon as I sign in the monitor connected with the DVI will go blank about 80% of the time.
My workaround solutions to fix this problem
- Going back to the login screen via CTRL + ALT + BACKSPACE and signing in again will almost always fix it.
- Physically removing/reinserting the cable will almost always fix it.
Behavior
- When logging in and experiencing the problem, the monitor seems to be recognized as I can move my mouse into its resolution, but the monitor claims cable not connected.
When did the problem occur?
- After moving and going from three to two monitors as well as reinstalling Linux Mint for luks encryption
I'm pretty green when it comes to diagnosing graphical problem. I would be happy to paste logs, but I'm not sure which ones would be helpful. Please let me know which logs might be worth taking a look at, or any other suggestions you may have!
----- Edits/ Additional Info -----
The issue is isolated with Linux as this machine can dual boot into windows without the described problem
$ lspci -k | grep -EA3 'VGA'
00:02.0 VGA compatible controller: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07)
Subsystem: Lenovo Skylake GT2 [HD Graphics 520]
Kernel driver in use: i915
Kernel modules: i915
|
$ cat /var/log/Xorg.0.log | grep -i driver
[ 105.041] X.Org Video Driver: 23.0
[ 105.041] X.Org XInput driver : 24.1
[ 105.062] (==) Matched modesetting as autoconfigured driver 0
[ 105.062] (==) Matched fbdev as autoconfigured driver 1
[ 105.062] (==) Matched vesa as autoconfigured driver 2
[ 105.062] (==) Assigned the driver to the xf86ConfigLayout
[ 105.062] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 105.063] Module class: X.Org Video Driver
[ 105.063] ABI class: X.Org Video Driver, version 23.0
[ 105.063] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 105.063] Module class: X.Org Video Driver
[ 105.063] ABI class: X.Org Video Driver, version 23.0
[ 105.063] (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so
[ 105.063] Module class: X.Org Video Driver
[ 105.063] ABI class: X.Org Video Driver, version 23.0
[ 105.063] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 105.063] (II) FBDEV: driver for framebuffer: fbdev
[ 105.063] (II) VESA: driver for VESA chipsets: vesa
[ 105.079] ABI class: X.Org Video Driver, version 23.0
[ 105.087] (II) glamor: OpenGL accelerated X.org driver based.
[ 105.946] (II) modeset(0): [DRI2] DRI driver: i965
[ 105.946] (II) modeset(0): [DRI2] VDPAU driver: i965
[ 106.020] Module class: X.Org XInput Driver
[ 106.020] ABI class: X.Org XInput driver, version 24.1