PRIME output slaves should be set up automatically
Submitted by pos..@..lfj.de
Assigned to Xorg Project Team
Link to original bug (#103213)
Description
Steps to reproduce
- On a laptop with an integrated and a dedicated GPU and some outputs connected the dedicated GPU, start X11.
- Plug a screen into the dedicated GPU's output.
- Run xrandr -q
Expected behavior
The external screen should be listed and configurable.
Actual behavior
No external screen is listed. I have to first run "xrandr --setprovideroutputsource 1 0". That is a problem in particular for graphical display managers -- getting a login on all connected screens requires somehow running this command in the DM session, which I have not yet managed to do reliably for gdm3.
Xorg clearly already knows which card is the primary card, because it can talk to my internal screen and "glxinfo" shows the Intel card, while "DRI_RPIME=1 glxinfo" shows the NVidia card. Given that it knows which card is the primary, Xorg should just add all other cards (that support it and that have outputs) as output slaves. That would significantly improve the out-of-the-box experience.
Further information
I have a Lenovo P50 and I am using Debian testing with Xorg 7.7 and Linux 4.12. The machine has its HDMI connector wired to the an NVidia GM107GLM (Quadro M2000M), while the internal display is driven by an Intel HD graphics P530 (Skylake GT2). On the Xorg side, both cards are using the modesetting driver. My DE is Gnome 3.26.
Version: 7.7 (2012.06)