Bug 97397

Summary: Kernel 4.7.x does nor initialize external DisplayPort in Dell E7250 making it unusable
Product: DRI Reporter: Łukasz Maśko <ed>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: CLOSED FIXED QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: major    
Priority: medium CC: intel-gfx-bugs, loirotte
Version: DRI git   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: BDW i915 features: display/DP
Attachments:
Description Flags
dmesg output
none
dmesg output on 4.6.7 - here it's fine
none
Dmesg for kernel 4.8.1 - still wrong here
none
dmesg with drm.debug=14 for kernel 4.8.0 none

Description Łukasz Maśko 2016-08-18 16:37:18 UTC 
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.
Comment 1 Jani Nikula 2016-08-18 17:57:25 UTC 
Does v4.8-rc2 work?

Can you bisect between 4.6 and v4.7?
Comment 2 Łukasz Maśko 2016-08-18 20:16:09 UTC 
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.
Comment 3 Łukasz Maśko 2016-10-10 10:24:11 UTC 
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.
Comment 4 Philippe Dosch 2016-11-03 17:45:46 UTC 
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)
Comment 5 Jani Nikula 2016-11-04 10:03:04 UTC 
(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.
Comment 6 Łukasz Maśko 2016-11-04 12:07:56 UTC 
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.
Comment 7 Jani Nikula 2016-11-04 14:33:04 UTC 
(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
Comment 8 Philippe Dosch 2016-11-04 15:46:52 UTC 
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).
Comment 9 Philippe Dosch 2016-11-04 15:56:29 UTC 
(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
Comment 10 Łukasz Maśko 2016-11-04 16:44:44 UTC 
(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.
Comment 11 Łukasz Maśko 2016-11-04 20:52:53 UTC 
(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.
Comment 12 Philippe Dosch 2016-11-05 09:23:46 UTC 
(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.
Comment 13 Philippe Dosch 2016-11-07 16:17:22 UTC 
(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
Comment 14 Jani Nikula 2016-11-07 18:38:06 UTC 
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+.
Comment 15 yann 2016-11-08 08:05:33 UTC 
closing then bug

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