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fredreichbier

Member

Registered: 2008-11-28

Posts: 6

[solved] Flickering screen when trying to set up dual head (intel)

Hey there,

I'm trying to get dual head support running on a Thinkpad T520 (using the integrated Intel graphics chip). When I try to initialize the external screen using `xrandr --output VGA1 --auto`, the second screen shows an image, but the notebook screen (LVDS1) shows a very distorted and flickering image. This doesn't change after doing `xrandr --output VGA1 --off`; even restarting the X server changes nothing. It's okay again after a reboot, though.

It looks like this: http://imgur.com/91uGl

Here's some information, let me know if you need more!

% xrandr -q
Screen 0: minimum 320 x 200, current 1600 x 900, maximum 8192 x 8192
LVDS1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1600x900       60.0*+   50.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 connected (normal left inverted right x axis y axis)
   1280x1024      60.0 +   75.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  

% glxinfo | head -n 20
name of display: :0.0
display: :0  screen: 0
direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.4
server glx extensions:
    GLX_ARB_multisample, GLX_EXT_import_context, GLX_EXT_texture_from_pixmap, 
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_MESA_copy_sub_buffer, 
    GLX_OML_swap_method, GLX_SGI_make_current_read, GLX_SGI_swap_control, 
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, 
    GLX_SGIX_visual_select_group, GLX_INTEL_swap_event
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context, 
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_EXT_framebuffer_sRGB, 
    GLX_MESA_copy_sub_buffer, GLX_MESA_multithread_makecurrent, 
    GLX_MESA_swap_control, GLX_OML_swap_method, GLX_OML_sync_control, 
    GLX_SGI_make_current_read, GLX_SGI_swap_control, GLX_SGI_video_sync, 
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,

% lshw
...
        *-display
             description: VGA compatible controller
             product: 2nd Generation Core Processor Family Integrated Graphics Controller
             vendor: Intel Corporation
             physical id: 2
             bus info: pci@0000:00:02.0
             version: 09
             width: 64 bits
             clock: 33MHz
             capabilities: msi pm vga_controller bus_master cap_list rom
             configuration: driver=i915 latency=0
             resources: irq:46 memory:f1400000-f17fffff memory:e0000000-efffffff ioport:6000(size=64)
...
% lspci
...
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
...

Does anybody have an idea how to fix that?

Cheers!

Fred

Last edited by fredreichbier (2011-10-29 17:32:58)

gorky

Member

From: Kraków, Poland

Registered: 2010-07-05

Posts: 96

Re: [solved] Flickering screen when trying to set up dual head (intel)

What do you want to achieve? Screen cloning, extended desktop? Try starting from:

xrandr --output LVDS1 --auto --output VGA1 --auto --right-of LVDS1

fredreichbier

Member

Registered: 2008-11-28

Posts: 6

Re: [solved] Flickering screen when trying to set up dual head (intel)

Hi gorky,

in the end, I want to achive an extended desktop with VGA1 being right of LVDS1, as your command says. However, this command and simple screen cloning both produce the effect above.

gorky

Member

From: Kraków, Poland

Registered: 2010-07-05

Posts: 96

Re: [solved] Flickering screen when trying to set up dual head (intel)

I assume you have the newest kernel and Intel drivers (3.0.4 && 2.16.0)?
I'd also try setting resolution manually instead of '--auto'.
Do you have any xorg.conf?

To me it seems like a driver or config issue, because I often configure second screen on T60 this way and everything works without problems...

Last edited by gorky (2011-09-29 15:22:19)

fredreichbier

Member

Registered: 2008-11-28

Posts: 6

Re: [solved] Flickering screen when trying to set up dual head (intel)

Hi, thanks for your answer and sorry for the delay!
Yep, it's 3.0.4 and 2.16.0 (since today), but this hasn't changed anything.
Nope, no xorg.conf, but some files in /etc/X11/xorg.conf.d, but these are evdev/synaptics-related, so I guess they don't have anything to do with that bug.

Hm well, since the behavior persists even after an X11 restart, I guess it's a driver problem?

Cheers!

gorky

Member

From: Kraków, Poland

Registered: 2010-07-05

Posts: 96

Re: [solved] Flickering screen when trying to set up dual head (intel)

If there are no graphic card related lines in files inside xorg.conf.d then it looks to me rather like a driver or hardware problem.

One more thing - I remember I had issues with second display when laptop was on battery power - now I'm connecting it to AC when using external monitor (my battery is dead anyway).
Can you confirm the problem persists when on AC? Also can you look for anything suspicious in Xorg.0.log ?

Last edited by gorky (2011-10-12 16:23:14)

fredreichbier

Member

Registered: 2008-11-28

Posts: 6

Re: [solved] Flickering screen when trying to set up dual head (intel)

Hey there!

No, I'm always using the AC Looking at `dmesg`, I found this:

[19144.860008] [drm:pch_irq_handler] *ERROR* PCH poison interrupt
[19187.735524] [drm:pch_irq_handler] *ERROR* PCH poison interrupt
[19736.522867] [drm:pch_irq_handler] *ERROR* PCH poison interrupt

which seems to be related to the intel driver, though I can't find these entries if I boot with the VGA plugged in (but the issue with the distorted screen persists).

And this in the xorg logs:

[ 19784.186] (II) intel(0): EDID vendor "LEN", prod id 16561
[ 19784.186] (II) intel(0): Printing DDC gathered Modelines:
[ 19784.186] (II) intel(0): Modeline "1600x900"x0.0   96.31  1600 1648 1680 1726  900 902 907 930 -hsync -vsync (55.8 kHz)
[ 19784.186] (II) intel(0): Modeline "1600x900"x0.0   80.63  1600 1648 1680 1734  900 902 907 930 -hsync -vsync (46.5 kHz)
[ 20235.210] (II) intel(0): EDID vendor "LEN", prod id 16561
[ 20235.210] (II) intel(0): Printing DDC gathered Modelines:
[ 20235.210] (II) intel(0): Modeline "1600x900"x0.0   96.31  1600 1648 1680 1726  900 902 907 930 -hsync -vsync (55.8 kHz)
[ 20235.210] (II) intel(0): Modeline "1600x900"x0.0   80.63  1600 1648 1680 1734  900 902 907 930 -hsync -vsync (46.5 kHz)
[ 20248.917] (II) intel(0): EDID vendor "LEN", prod id 16561
[ 20248.917] (II) intel(0): Printing DDC gathered Modelines:
[ 20248.917] (II) intel(0): Modeline "1600x900"x0.0   96.31  1600 1648 1680 1726  900 902 907 930 -hsync -vsync (55.8 kHz)
[ 20248.917] (II) intel(0): Modeline "1600x900"x0.0   80.63  1600 1648 1680 1734  900 902 907 930 -hsync -vsync (46.5 kHz)
[ 20248.991] (II) intel(0): Allocated new frame buffer 1600x1024 stride 6656, tiled
[ 20255.413] (II) intel(0): EDID vendor "LEN", prod id 16561
[ 20255.413] (II) intel(0): Printing DDC gathered Modelines:
[ 20255.413] (II) intel(0): Modeline "1600x900"x0.0   96.31  1600 1648 1680 1726  900 902 907 930 -hsync -vsync (55.8 kHz)
[ 20255.413] (II) intel(0): Modeline "1600x900"x0.0   80.63  1600 1648 1680 1734  900 902 907 930 -hsync -vsync (46.5 kHz)

But this looks correct to me.

Anyway, thanks for your help so far!

fredreichbier

Member

Registered: 2008-11-28

Posts: 6

Re: [solved] Flickering screen when trying to set up dual head (intel)

Hey there!

I think I just solved the problem, or at least found a workaround: Using the preferred refresh rate of 60.0Hz is the problem:

xrandr --output VGA1 --mode 1280x1024 --rate 60.0

-> VGA1 is fine, LVDS1 is flickering as shown in the image I posted.

xrandr --output VGA1 --mode 1280x1024 --rate 75.0

-> both are fine.

So, don't ask me why, but it works fine if I use a refresh rate of 75Hz.

Thank you again for your help, gorky!

Cheers!

Friedrich