Created attachment 125882 [details] dmesg output $ uname -a Linux laptok 4.7.1-1 #1 SMP Wed Aug 17 19:12:42 CEST 2016 x86_64 Intel(R)_Core(TM)_i5-5300U_CPU_@_2.30GHz PLD Linux Machine: Dell Latitude E7250 Kernel 4.7.x does not initialize the external DisplayPort in my laptop. During start it throws in the logs: [drm:intel_dp_start_link_train [i915]] *ERROR* failed to train DP, aborting (full log in the attached dmesg output) and does not allow me to use the external display connected to this output. It does not matter, it the external screen is connected at boot time or not - it is not visible in the system. Everything works fine with kernel 4.6.4 - I can connect external display on the fly (I use DP-to-VGA converter for I usually use this port for presentations for my students). The internal eDP screen works fine and without any problems with both 4.6.x and 4.7.x kernels. This behaviour is 100% reproducible on my hardware.
Does v4.8-rc2 work? Can you bisect between 4.6 and v4.7?
Created attachment 125891 [details] dmesg output on 4.6.7 - here it's fine I have not tried 4.8 release candidates. 4.6.7 (the last from the 4.6.x line) works fine. 4.7.0 (the first from the 4.7.x line) has the reported error. I cannot check 4.7 release candidates due to lack of resources.
Created attachment 127162 [details] Dmesg for kernel 4.8.1 - still wrong here This is a dmesg output obtained on kernel 4.8.1. I still can observe the "link training" errors here.
Hi, It seems that I meet the same bug after having upgraded from ubuntu 16.04 to ubuntu 16.10. I'm now with a 4.8.0 kernel. Since the upgrade, I'm unable to connect a video projector on my VGA port (whereas it has perfectly worked with the two former releases). Strangely, if I connect an external monitor with the same resolution than my laptop (1920x1080), the monitor is detected and works. After having met Lukasz on the Xorg ML, I've tried to boot on a 4.6.3 kernel and I'm now able to make the video projector works. Details on my configuration =========================== Laptop HP EliteBook 840 with a i915 graphics card using kubuntu 16.10, and a video projector connected to the VGA port. 1) Kernel 4.8.0 ------------ phil@IUTNC-DOSCH i915 % uname -a Linux IUTNC-DOSCH 4.8.0-26-generic #28-Ubuntu SMP Tue Oct 18 14:39:52 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux When I boot, the message "[drm:intel_dp_start_link_train [i915]] *ERROR* failed to update link training" appears 3 times in dmesg. phil@IUTNC-DOSCH i915 % xrandr Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192 eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 173mm 1920x1080 60.05*+ 59.93 1680x1050 59.95 59.88 1600x1024 60.17 1400x1050 59.98 1280x1024 60.02 1440x900 59.89 1280x960 60.00 1360x768 59.80 59.96 1152x864 60.00 1024x768 60.04 60.00 960x720 60.00 928x696 60.05 896x672 60.01 960x600 60.00 960x540 59.99 800x600 60.00 60.32 56.25 840x525 60.01 59.88 800x512 60.17 700x525 59.98 640x512 60.02 720x450 59.89 640x480 60.00 59.94 680x384 59.80 59.96 576x432 60.06 512x384 60.00 400x300 60.32 56.34 320x240 60.05 DP-1 disconnected (normal left inverted right x axis y axis) HDMI-1 disconnected (normal left inverted right x axis y axis) DP-2 disconnected (normal left inverted right x axis y axis) HDMI-2 disconnected (normal left inverted right x axis y axis) 2) Kernel 4.6.3 ------------ phil@IUTNC-DOSCH ~ % uname -a Linux IUTNC-DOSCH 4.6.3-040603-generic #201606241434 SMP Fri Jun 24 18:36:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux When I boot, there is none message as the one above (so no more error message about the i915 card). Even if the video projector is physically connected to the VGA port, it seems it is logically seen as a DP one: phil@IUTNC-DOSCH testkern % xrandr Screen 0: minimum 320 x 200, current 1920 x 1848, maximum 8192 x 8192 eDP-1 connected primary 1920x1080+0+768 (normal left inverted right x axis y axis) 309mm x 173mm 1920x1080 60.05*+ 59.93 1680x1050 59.95 59.88 1600x1024 60.17 1400x1050 59.98 1280x1024 60.02 1440x900 59.89 1280x960 60.00 1360x768 59.80 59.96 1152x864 60.00 1024x768 60.04 60.00 960x720 60.00 928x696 60.05 896x672 60.01 960x600 60.00 960x540 59.99 800x600 60.00 60.32 56.25 840x525 60.01 59.88 800x512 60.17 700x525 59.98 640x512 60.02 720x450 59.89 640x480 60.00 59.94 680x384 59.80 59.96 576x432 60.06 512x384 60.00 400x300 60.32 56.34 320x240 60.05 DP-1 disconnected (normal left inverted right x axis y axis) HDMI-1 disconnected (normal left inverted right x axis y axis) DP-2 connected 1024x768+424+0 (normal left inverted right x axis y axis) 0mm x 0mm 1024x768 60.00* 800x600 60.32 56.25 848x480 60.00 640x480 59.94 HDMI-2 disconnected (normal left inverted right x axis y axis)
(In reply to Philippe Dosch from comment #4) > It seems that I meet the same bug after having upgraded from ubuntu > 16.04 to ubuntu 16.10. I'm now with a 4.8.0 kernel. Since the upgrade, > I'm unable to connect a video projector on my VGA port (whereas it has > perfectly worked with the two former releases). This bug is about display port, not VGA. Please file a new bug.
The VGA port in this case is in fact connected via DP port. Have a look in the comments above. It seems to be the same issue. By the way - kernel 4.8.6 and still no good.
(In reply to Łukasz Maśko from comment #6) > The VGA port in this case is in fact connected via DP port. Have a look in > the comments above. It seems to be the same issue. Right, the information about that was buried in the middle of it all. Philippe, please add drm.debug=14 module parameter and attach dmesg from boot to the problem. > By the way - kernel 4.8.6 and still no good. Please try drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel
Created attachment 127762 [details] dmesg with drm.debug=14 for kernel 4.8.0 Obtained at boot time of my HP EliteBook 840, when VGA/DP of integrated i915 does not work (external monitor with same resolution as my laptop is recognized, video projector is *not* recognized).
(In reply to Jani Nikula from comment #7) > (In reply to Łukasz Maśko from comment #6) > > The VGA port in this case is in fact connected via DP port. Have a look in > > the comments above. It seems to be the same issue. > > Right, the information about that was buried in the middle of it all. > Philippe, please add drm.debug=14 module parameter and attach dmesg from > boot to the problem. Done. Do you want the same with a boot of my 2.6.3 kernel? Philippe
(In reply to Philippe Dosch from comment #8) [..] > (external monitor with same resolution as my laptop is > recognized, video projector is *not* recognized). Same for me. Although the monitor is recognized as DP1-1 and connected via DVI connector.
(In reply to Łukasz Maśko from comment #10) [...] > > By the way - kernel 4.8.6 and still no good. > > Please try drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel OK. Accept my apolgies - it seems to WORK on 4.8.6. I have just tried it and after using a VGA connector, I have an output on external screen (my external connector is connected through DP2 graphics output). The only thing is that I have only resolutions up to 1024x768, nothing higher. It may be caused by my DP-to-VGA adapter, I'll have to borrow another one and try. Anyway - Philippe Dosch, try 4.8.6 if you can. Maybe it will also fix your problem.
(In reply to Łukasz Maśko from comment #11) > (In reply to Łukasz Maśko from comment #10) > [...] > > > By the way - kernel 4.8.6 and still no good. > > > > Please try drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel > > OK. Accept my apolgies - it seems to WORK on 4.8.6. I have just tried it and > after using a VGA connector, I have an output on external screen (my > external connector is connected through DP2 graphics output). The only thing > is that I have only resolutions up to 1024x768, nothing higher. It may be > caused by my DP-to-VGA adapter, I'll have to borrow another one and try. > > Anyway - Philippe Dosch, try 4.8.6 if you can. Maybe it will also fix your > problem. I'll give it a try Monday, I don't have access to video projectors on weekends. Thanks anyway, I keep you in touch.
(In reply to Łukasz Maśko from comment #11) > (In reply to Łukasz Maśko from comment #10) > [...] > > > By the way - kernel 4.8.6 and still no good. > > > > Please try drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel > > OK. Accept my apolgies - it seems to WORK on 4.8.6. I have just tried it and > after using a VGA connector, I have an output on external screen (my > external connector is connected through DP2 graphics output). The only thing > is that I have only resolutions up to 1024x768, nothing higher. It may be > caused by my DP-to-VGA adapter, I'll have to borrow another one and try. It seems also to work for me with a 4.8.6 kernel! phil@IUTNC-DOSCH ~ % uname -a Linux IUTNC-DOSCH 4.8.6-040806-generic #201610310831 SMP Mon Oct 31 12:33:48 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux Philippe
Looking at commits in range v4.8.1..v4.8.6, I presume this was fixed in v4.8.6 by commit 44e58783adf5e3a365516ae324e74621751b0626 Author: Ville Syrjälä <ville.syrjala@linux.intel.com> Date: Mon Oct 3 10:55:16 2016 +0300 drm/i915: Allow DP to work w/o EDID commit 16c83fad79ca912b8b5bbdcb5272794a2be41262 upstream. Closing. Please reopen if the problem persists with v4.8.6+ or v4.9-rc1+.
closing then bug
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