Cloning screen to an external monitor using fglrx

Majkl578 · 09-14-2009, 08:31 AM

Hello, it's the first time I'm writing here.

I'm having troubles with cloning my desktop on an external monitor.

I'm running Debian Lenny (sid updates) on kernel 2.6.30 and FGLRX installed via official installer (ati-driver-installer-9-3-x86.x86_64.run). Kernel module does not work (compilation failure), but it only disallows me to probe it and use OpenGL.
I've ASUS F3KE laptop with ATI Mobility Radeon X2300.

Now, I'm trying to clone (mirror) my desktop to an external monitor. I use 1280x800 as a resolution for my laptop. External monitor (in fact, it's NEC projector) has maximal resolution 1024x768. On MS Windows, it worked perfectly, it automatically resized output to fit there (with respect to 16:10). The problem is that resolution on external monitor is being set incorrectly.

I tried a lot of possibilities (amdcccle, xorg.conf modifications, etc) which I've found on internet, but none of them works...

Any suggestions how to make the output to behave and be resized correctly?

Simon Bridge · 09-14-2009, 08:42 AM

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FGLRX installed via official installer

Why not use the official lenny package. Be aware that the official installer has been known no hose systems, though not for a while.

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Kernel module does not work (compilation failure), but it only disallows me to probe it and use OpenGL.

That means it is not going.
You are probably still using a free software driver.
Verify by checking your xorg.conf

xrandr handles automagically cloning for external monitors - though often you find that the internal screen gets the lower resolution. Lenny should be set up for this already.

IIRC: glrx also has its own cloning method.
With this information, I will advise: uninstall the driver, restore the old xorg.conf then use the free software drivers to work out the cloning issues. If you still want 3D acceleration, install the lenny package with apt.

So, you are expecting 1024x768 - what are you getting?

Majkl578 · 09-14-2009, 08:58 AM

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hy not use the official lenny package.

I tried official packages, but these are not working yet (there's a bug in kernel module). It also requires newer xserver which is not compatible with gsynaptics. :/

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Verify by checking your xorg.conf

My actual xorg.conf is here: http://lq.majkl578.cz/xorg.conf
I think it's correct - driver is fglrx

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So, you are expecting 1024x768 - what are you getting?

I'm expecting to have 1280x800 on my laptop and cramped version of it (with black zones on the top and bottom) on 1024x768 (as it is external monitor's maximum).
I'm getting incomplete desktop - when I move a cursor to different corner, it moves because 1280x800 is too large...

Simon Bridge · 09-14-2009, 09:20 AM

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I think it's correct - driver is fglrx

... that cannot be correct because you do not have the fglrx driver installed.

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when I move a cursor to different corner, it moves because 1280x800 is too large...

Cool! I've not seen that before... it sounds like it is working then - though it's normally the other way round.

Here's what normally happens - on projector you get a full size desktop filling the screen (no black bits) at 1024x768, on your laptop, the screen resizes to 1024x768. It sounds like you have 1280x800 on both screens, and the whole desktop shifts with mouse movements - like it is zoomed, like super+mouse wheel in compiz.

I have seen this happen on a laptop screen when the external monitor has a higher resolution ... in which case the laptop gets the zoomed desktop.

So - resize your screen to 1024x768 when you do presentations.

I suspect you need to add modelines to the display sections of xorg.conf to make this work automatically.
But you really should get that driver compiled.

The most common compiler error is due to missing headers.

Majkl578 · 09-14-2009, 10:15 AM

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The most common compiler error is due to missing headers.

The problem is not in compiling the module, but in "modprobe fglrx", it can't allocate memory (dunno where the problem is).

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So - resize your screen to 1024x768 when you do presentations

If this is the only one solution, I've no other choice...
But I'm used to have a comfort from windows.. - 1280x800 on my laptop and resized 1280x800 on external 1024x768 monitor...

Finally I removed ATI proprietary, updated xserver to 7.4 (with its subcomponents like drivers) and got X working thru free driver.

But the point of this topic has not been solved yet. :/

Simon Bridge · 09-14-2009, 10:51 AM

You have two issues -

1. installing fglrx. Lets deal with that later.
2. external monitor resolution - you want external monitor to have correct resolution - you are prepared to allow the internal to be lower for the presentation?

The workaround suggested is resizing the resolution to 1024x768 for presentations. This is easiest but uncomfortable, especially if you do a lot of presentations.

The next thing you did not mention trying was adding modes to xorg.conf display subsection so X does not have to guess the correct resolution. Have you tried that?

I'm guessing your xorg.conf is different now.

Next time you have the external plugged in, open a terminal and try:

$ sudo dpkg-reconfigure -phigh xserver-xorg
Then check your xorg.conf to see if extra entries have been added.

xrandr

this should give you a list of monitors (by output) and resolutions. If vga is not connected to anything it will just say so.

xrandr --output VGA --mode 1024x768

should do the trick - provided VGA is the external of course.
If you are using the radeon driver, then that will be vga-0

BUT, this is the same as adding modes to xorg.conf

How about:

xrandr --output VGA --right-of LVDS

Now it's dual head.

xrandr --output LVDS --rotate left

A decent guide for configuring xorg.conf for xrandr - see
http://www.thinkwiki.org/wiki/Xorg_RandR_1.2#xorg.conf

Majkl578 · 09-14-2009, 12:17 PM

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installing fglrx. Lets deal with that later.

I am not able to use fglrx until the bug will be fixed.

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I'm guessing your xorg.conf is different now.

here it is: http://lq.majkl578.cz/xorg.conf~2

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$ sudo dpkg-reconfigure -phigh xserver-xorg
Then check your xorg.conf to see if extra entries have been added.

there is no difference after running this command.

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xrandr

this should give you a list of monitors (by output) and resolutions. If vga is not connected to anything it will just say so.

yep, output is:

Code:

Screen 0: minimum 320 x 200, current 1280 x 800, maximum 1280 x 1280
VGA-0 connected (normal left inverted right x axis y axis)
   800x600        60.3 +   85.1     72.2     75.0     60.3     56.2  
   1024x768       85.0     75.0     70.1     60.0  
   832x624        74.6  
   640x480        85.0     75.0     72.8     66.7     59.9  
   720x400        70.1  
LVDS connected 1280x800+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1280x800       60.0*+
   1280x720       59.9  
   1152x768       59.8  
   1024x768       60.0     59.9  
   800x600        60.3     59.9  
   640x480        59.9     59.4  
DVI-0 disconnected (normal left inverted right x axis y axis)

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xrandr --output VGA --mode 1024x768

should do the trick - provided VGA is the external of course.
If you are using the radeon driver, then that will be vga-0

this does what I want, but the problem with different resolution persists (using 1280x800 ).

Quote:

How about:

xrandr --output VGA --right-of LVDS

Now it's dual head.

xrandr --output LVDS --rotate left

Well I think this isn't what I want to do. This does not clone the laptop's desktop, but extends it to an external monitor.

So, I see there is probably no other possibility how to do it without changing notebook's resolution (maybe fglrx can do it, but can't try it)....