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saciel

Member

From: Germany

Registered: 2006-07-30

Posts: 153

X11/Framebuffer conflict, probably... consoles get messed up

For a few days now, I occasionally run into problems with X11 and my text consoles. After starting the xserver, they all black out and I don't see nothing but a black screen. However, they are still there, I can (blindly) log in and execute any commands from the consoles.
So far, I've found no way to get them working again but rebooting.

It's annoying, as I use the consoles for just about anything, including email (mutt), instant messageing (finch), and so on.

Any ideas what could be the problem or how it could be resolved? I haven't changed anything lately, except of a bigger system update a few days ago, but I'm not quite sure if this was before or after I ran into the problems.

I'm running the "intel" video drivers for X, and set the framebuffer-resolution to the same value via grub kernel-line.

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They say if you reverse play a Windows CD you can hear satanic verses... But wanna know what's even worse? If you forward play it, it's gonna install Windows on your system!

dav7

Member

From: Australia

Registered: 2008-02-08

Posts: 674

Re: X11/Framebuffer conflict, probably... consoles get messed up

AGH.

AGH Agh agh agh agh.

You have the same problem as me. You're going to have to disable framebuffer consoles, I'm sorry, and you're also going to have to minimize your resolution changes - that's what causes it to happen.

If you're REALLY lucky, you'll find 9865638625 "(EE) intel(0): buffer underrun on pipe A!" messages in some X logs somewhere, or even printed at the (invisible for you right now) consoles.

And... set your expectations to 0, because as far as I can see there's absolutely no way to fix this except reboot.

Pst. By the way, if your chipset ever behaves like it just had a fight with your mouse and the mouse won, please video the results if you can what happens is that the mouse Y axis seems to control the screen height and the X axis controls the horizontal centering. I haven't seen the bug in a while, but next time it happens I WILL be doing my best to video it

-dav7

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Windows was made for looking at success from a distance through a wall of oversimplicity. Linux removes the wall, so you can just walk up to success and make it your own.
--
Reinventing the wheel is fun. You get to redefine pi.

saciel

Member

From: Germany

Registered: 2006-07-30

Posts: 153

Re: X11/Framebuffer conflict, probably... consoles get messed up

So I finally got some sort of solution to it, although I haven't quite figured out what actually causes the problem. First I found out, that the problem did not occur with my old configuration and 'i810' drivers, only with 'intel' drivers. However, the 'i810' package has been discontinued quite a while ago. Anyhow, using my old configuration (where I managed dualhead with two seperate device entries and different serverlayouts) adapted to 'intel' drivers I could get rid of the blackout.

These are extracts from my original 'intel' xorg.conf (not the adapted 'i810 one):

Section "Device"

    Identifier    "Intel 945GM"
    BusID        "PCI:0:2:0"
    Driver        "intel"

    Option  "monitor-LVDS"    "x60 TFT"
    Option  "monitor-VGA"    "output VGA"

EndSection

Section "Screen"

    Identifier    "xrandr screen"
    Device        "Intel 945GM"
    Monitor        "x60 TFT"
    DefaultDepth    24

    Subsection "Display"
        Depth        24
        Modes        "1024x768" "800x600" "640x480"
        ViewPort    0 0
        Virtual        2704 2448
    EndSubsection

EndSection

Section "ServerLayout"

    Identifier    "xrandr"

    Screen        "xrandr screen"

    InputDevice    "Mouse1"    "CorePointer"
    InputDevice    "Keyboard1"    "CoreKeyboard"

EndSection

This setup worked (i.e. no console blackout) if and only if I really had a second monitor connected and was using it with xrandr. If there was no monitor connected to my laptop, I would get my console blacked out.

If I now disable all dual head features from the above code, that means the lines 'Virtual in 'Screen' and both 'Options' in 'Device', there is no more blackout (however, of course, dualhead is working no more).

The nice thing with xrandr is that you can add/disconnect monitors while keeping X running which wasn't possible with 'i810' and the static configuration.
Anyhow, my 'solution' to the problem is as follows:

Creating two almost identical Devices and Screens, one with the dualhead-lines, and one without, as well as two different ServerLayouts, one using the xrandr-screen, one using the nonxrand-screen.

If I have no monitor connected I have to start with 'startx -layout single' and get no blackout but cannot use dualhead without restarting X. If I have a monitor connected I use 'startx -layout xrandr' and will get no blackout as long as I do not disconnect the montior while X is running.

The curious thing is, that if I get a blackout, for example because I started layout xrandr with no monitor I can 'cure' it by restarting X with layout single. X starts and the consoles are all fine again.

So finally, this is how the relevant part of my xorg.conf looks now:

Section "Device"

    # for dual head setup:

    Identifier    "Intel 945GM"
    BusID        "PCI:0:2:0"
    Driver        "intel"

    Option  "monitor-LVDS"    "x60 TFT"
    Option  "monitor-VGA"    "output VGA"

EndSection

Section "Device"

    # to prevent console blackout with single head:

    Identifier    "Intel 945GM single"
    BusID        "PCI:0:2:0"
    Driver        "intel"

EndSection

Section "Screen"

    # for dual head setup:

    Identifier    "xrandr screen"
    Device        "Intel 945GM int"
    Monitor        "x60 TFT"
    DefaultDepth    24

    Subsection "Display"
        Depth        24
        Modes        "1024x768" "800x600" "640x480"
        ViewPort    0 0
        Virtual        2704 2448
    EndSubsection

EndSection

Section "Screen"

    # to prevent console blackout with single head:

    Identifier    "single screen"
    Device        "Intel 945GM int single"
    Monitor        "x60 TFT"
    DefaultDepth    24

    Subsection "Display"
        Depth        24
        Modes        "1024x768" "800x600" "640x480"
        ViewPort    0 0
    EndSubsection

EndSection

Section "ServerLayout"

    # for dual head setup:

    Identifier    "xrandr"

    Screen        "xrandr screen"

    InputDevice    "Mouse1"    "CorePointer"
    InputDevice    "Keyboard1"    "CoreKeyboard"

EndSection

Section "ServerLayout"

    # to prevent console blackout with single head:

    Identifier    "single"

    Screen        "single screen"

    InputDevice    "Mouse1"    "CorePointer"
    InputDevice    "Keyboard1"    "CoreKeyboard"

EndSection

Maybe this helps you, or anybody else, or makes somebody have an idea on how to really solve the problem.

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They say if you reverse play a Windows CD you can hear satanic verses... But wanna know what's even worse? If you forward play it, it's gonna install Windows on your system!

saciel

Member

From: Germany

Registered: 2006-07-30

Posts: 153

Re: X11/Framebuffer conflict, probably... consoles get messed up

I've taken some time to further examine the problem and I finally found which setting is responsible (I don't see the reason, though.) for the 'blackout'.

If one of the dimensions of Screen's 'Virtual' exceeds 2048 then there is the blackout, if Virtual is kept below 2048x2048 I can use dualhead without the blackout.

Seems I got to place my external monitor above my laptop in 'landscape' orientation and left of it in 'portrait' orientation to stay in bounds. Until now I had just configured it the other way round.

---

They say if you reverse play a Windows CD you can hear satanic verses... But wanna know what's even worse? If you forward play it, it's gonna install Windows on your system!