libdrm2 update causes xorg freeze with r128 driver

Using Ubuntu's stable 14.04 branch; X.Org X Server 1.15.1; Ati Rage R128 module v. 6.9.2
, on restart after updating libdrm2 to version libdrm2_2.4.60-2~ubuntu14.04
xorg froze immediately after a reboot;
Upon closer inspection, I was able to switch out to a virtual console, after pressing the appropriate keys, but only after a very unusually long delay. In another attempt starting Xorg I noticed that it seemed something was actually rendered, even if just a single frame in a few minutes..

Downgrading libdrm2 to version 2.4.52-1 restored Xorg to its usual behavior; therefore libdrm2 seems the likely culprit of this problem, which perhaps only occurs in conjunction with the usage of this not very common r128 module

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: libdrm2 2.4.60-2~ubuntu14.04.1
ProcVersionSignature: Ubuntu 3.13.0-34.60-generic 3.13.11.4
Uname: Linux 3.13.0-34-generic i686
ApportVersion: 2.14.1-0ubuntu3.10
Architecture: i386
CurrentDesktop: LXDE
Date: Thu May 14 17:31:39 2015
Dependencies:
 gcc-4.9-base 4.9.1-0ubuntu1
 libc6 2.19-0ubuntu6.6
 libgcc1 1:4.9.1-0ubuntu1
 multiarch-support 2.19-0ubuntu6.6
InstallationDate: Installed on 2014-08-16 (271 days ago)
InstallationMedia: Lubuntu 14.04.1 LTS "Trusty Tahr" - Release i386 (20140722.2)
SourcePackage: libdrm
UpgradeStatus: No upgrade log present (probably fresh install)