Mouse pointer invisible - intel 945GM

Question

Hey people, thought I would document this in case others have problems.  I have partially solved the issue, but if someone knows a better solution please contribute.  I think this is specific to the intel xorg driver but not totally sure.
I rebooted my eeepc (Intel 945GM, using stock driver) today and when I got into X there was no mouse pointer.  I quickly found that the mouse is in fact there, you can right-click and get a menu etc, its just there is no pointer so your flying blind.
A bit of Googling suggested it was something to do with using xrandr to enable/disable outputs, which is what I do.  At home the eeepc sits on the desk connected to my external monitor.  In my .xinitrc I have it set up so it detects when its connected to the monitor and automatically enables it (VGA) and disables the laptop screen (LVDS).
So to try and get the mouse back I re-enabled the LVDS
xrandr --output LVDS --auto
The eeepc screen comes back on (in clone mode) and sure enough the mouse pointer is visible on that screen, but not on the external VGA.  After a bit of tooling around I found that if you enable both screens in extended desktop mode, the pointer is then visible on both.
xrandr --output LVDS --right-of VGA --auto
Once the pointer is working on both screens you can then turn off the LVDS again, and the pointer remains working on the external, everything back to normal.
xrandr --output LVDS --off
PART 2 - This is actually a question if anyone can help me
In order to use dual monitors like an extended desktop, you will find that you need to set the virtual desktop size in your xorg.conf display section.  Something like:
virtual 2304 1024
BUT...since we now bask in the glory that is hot-plugging and hal wizardry, I don't have an xorg.conf.  Does anyone know how to set the virtual framebuffer size using xrandr, without having to use an xorg.conf?
And while I think about it, why do we even need to set a virtual size manually really, xorg knows the dimensions of connected displays, you would think it could set a default virtual framebuffer to the width of the connected outputs, would make it much easier. /rant
Anyway, any more info on the subject much appreciated.
Last edited by Wittfella (2009-10-22 14:36:09)

Answer 1

The cursor issue sounds like an upstream bug - you should report it to https://bugs.freedesktop.org.
Wittfella wrote:Does anyone know how to set the virtual framebuffer size using xrandr, without having to use an xorg.conf?
Can't be done.  The virtual fb size tells your graphics driver how big a framebuffer to allocate at X start time.  It can't be changed later.  Which is too bad, and a major limitation of randr.  I think it does set the virtual fb size correctly when it starts, but that size will be wrong when you add another monitor for example.