How to correctly patch xrandr to resolve the scaling bug?

Question

I have the xrandr scaling bug described in: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/883319

(In short: I have a HiDPI laptop + an external monitor. When connected, the external monitor has blurry display due to having a different DPI from my laptop's internal display. I wanted to fix the issue using the xrandr --scale 2x2 command. However, there is an aforementioned bug that constraints the mouse movement on the external display to a quarter of the screen.)

From the bug thread it is apparent that there is a patch for this problem created by Chris Wilson: (https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/883319/+attachment/4399679/+files/randr_scaling_ubuntu1504.patch)

However, as I am a UNIX newbie it is not completely apparent to me how the patch should be installed so xrandr scaling works correctly again. Can anyone please post a more elaborate description of how to fix xserver using the above mentioned patch?

I am running Ubuntu-Gnome 14.04 LTS

Thanks

Answer 1

I also had the scaling issue. Here's how I patched it:

Download the source and patch for the xserver-xorg-core package.

mkdir src && cd src

apt-get source xorg-server  # or `git clone git://anongit.freedesktop.org/xorg/xserver` and checkout your version tag

cd xorg-xserver-x.xx.x/randr

wget https://bugs.freedesktop.org/attachment.cgi?id=94929 -O randr.patch

Patch xrandr:

patch -p1 < randr.patch

At

File to patch:

type:

rrcrtc.c

Install build dependencies:

sudo apt-get build-dep xserver-xorg-core

Install more build packages:

sudo apt-get install build-essential devscripts fakeroot

Compile the package:

cd ..

debuild -us -uc -i -I

Install the new package:

sudo dpkg -i xserver-xorg-core_x.xx.x-x.deb

Restart your DE and xrandr should now scale perfectly!