Ability to set correct DPI in 12.04 (still forced to 96?)

[Ryan Hayle]

It seems that there is no longer a way to set the correct DPI for a
particular screen.  I'm testing 12.04 on a MacBook with a 110 DPI
screen.  This is correctly detected by Xorg (107x103 detected by
nvidia driver in Xorg log file), however xdpyinfo shows the resolution
is still set to 96 DPI.  I don't even know what layer of
Xorg/GNOME/Unity is causing this problem, so I'm not sure where to
file a proper bug report anymore.  It seems like a rather serious
issue to fix before 12.04 is released for 5 years!

There is already a wishlist bug to add this to the Displays control
panel: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/8357

It should presented in such a way that users understand that this is a
physical characteristic of their display that must be correct and
should never be changed.  I guess GNOME 3 also text-scaling-factor
setting which is useful, but should not be confused with the physical
DPI characteristic.  Unfortunately it seems this is not quite the same
as a UI-scaling property which would resize UI elements as well, which
is what we really need.  Thoughts?  What am I missing here?  My main
laptop has as 147 screen, and I would never want a lower resolution
screen again, so I really hope to see this issue finally fixed!

--
Ryan