Created attachment 135926 [details] kernel log
Tests steps: Plug two external monitors, one of the is not displaying video signal unplug the second one, it turns on the first monitor, plug again the monitor don't reproduce video signal ====================================== Graphic stack ====================================== ====================================== Software ====================================== kernel version : 4.14.0-drm-tip-ww47-commit-f710441+ hostname : KBL-01 architecture : x86_64 os version : Ubuntu 17.04 os codename : zesty kernel driver : i915 bios revision : 1.46 bios release date : 09/20/2016 ksc : 1.36 hardware acceleration : enabled swap partition : enabled on (/dev/sda2) ====================================== Graphic drivers ====================================== mesa : 17.4.0-devel (git-ce221cbbcf modesetting : enabled modesetting compiled for : 1.19.99.1 X.Org Video Driver libdrm : 2.4.88 vaapi (intel-driver) : Intel i965 driver for Intel(R) Sandybridge Mobile - 2.0.1.pre1 (2.0.0.pre2-11-g35fc70f) cairo : 1.15.9 intel-gpu-tools (tag) : intel-gpu-tools-1.20-117-gf8f6db9c intel-gpu-tools (commit) : f8f6db9c ====================================== Hardware ====================================== motherboard model : 4243G52 motherboard id : 4243G52 form factor : Notebook manufacturer : LENOVO cpu family : Core i5 cpu family id : 6 cpu information : Intel(R) Core(TM) i5-2540M CPU @ 2.60GHz gpu card : Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller]) memory ram : 3.74 GB max memory ram : 16 GB display resolution : 1920x1080 cpu thread : 4 cpu core : 2 cpu model : 42 cpu stepping : 7 socket : ZIF Socket signature : Type 0, Family 6, Model 42, Stepping 7 hard drive : 447GiB (480GB) current cd clock frequency : 400000 kHz maximum cd clock frequency : 400000 kHz displays connected : LVDS-1 ====================================== Firmware ====================================== ====================================== kernel parameters ====================================== quiet splash drm.debug=0xe resume=/dev/sda2
Created attachment 135927 [details] dmesg log
First of all. Sorry about spam. This is mass update for our bugs. Sorry if you feel this annoying but with this trying to understand if bug still valid or not. If bug investigation still in progress, please ignore this and I apologize! If you think this is not anymore valid, please comment to the bug that can be closed. If you haven't tested with our latest pre-upstream tree(drm-tip), can you do that also to see if issue is valid there still and if you cannot see issue there, please comment to the bug.
This is still easily reproduce with 4.16.0-rc7-commit617cddf0. Whenever SNB laptop has DP and VGA connected the video signal will be lost in both monitors. If i use $ xrandr --output VGA-1 --auto I'll get video in the VGA monitor, but if I do $ xrandr --output DP-1 --auto It will return: xrandr: cannot find crtc for output DP-1 If only is used one output at the time, besides the laptop's display (LVDS-1), it works properly.
Ville, any advice here?
(In reply to Elizabeth from comment #4) > This is still easily reproduce with 4.16.0-rc7-commit617cddf0. Whenever SNB > laptop has DP and VGA connected the video signal will be lost in both > monitors. > If i use > > $ xrandr --output VGA-1 --auto > > I'll get video in the VGA monitor, but if I do > > $ xrandr --output DP-1 --auto > > It will return: > > xrandr: cannot find crtc for output DP-1 > > If only is used one output at the time, besides the laptop's display > (LVDS-1), it works properly. SNB only has two pipes so you can only drive two independent displays. To get three outputs at the same time you need to make sure two of the outputs are VGA and HDMI, and that they are using the exact same mode. Ie. you can simply never enable DP+VGA+LVDS simultaneously on SNB.
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