1
2
Hardware: I have a company-issued laptop (Dell E7440) on which I have installed CentOS 7; 2 Dell monitors which support VGA, DisplayPort, and DVI; and a Dell docking station for the laptop (indeterminate dock model). The dock has outputs for DVI, DP, and VGA. The laptop has outputs for HDMI and miniDP. The graphics on the laptop are Intel 4000 series integrated graphics.
Goal: I would like to be able to use the two external displays in "extended" mode (ie not mirrored), with the dock if possible.
Problem: When using the dock, all connected displays are seen as a single device (eDP1 in xrandr). Whether one or both monitors are connected, whether by DVI or VGA or DP or a mix, they just show up and are treated as a single output. This means that not only are the displays mirrored, but there is no way to un-mirror them.
What I've tried: Aside from mixing and matching cables on the dock, I have tried using the miniDP from the laptop, converting it to DVI, and using that with DisplayPort from the dock. This allows the OS to see both connected monitors, but it fails to display to either of them. I have also come across this, which seems perfect except that the instructions are for Debian-based systems. I don't have enough experience compiling kernels outside of a Gentoo install to know what the CentOS analogue for that process is.
Question: Can anyone either A) tell me the CentOS commands for the steps in the link above, or B) point me to another potential solution (or a specific root cause which I could research further)?
YouAreTheHat
Posted 2015-01-19T15:51:11.837
Reputation: 33