fglrx-core 2:14.501-0ubuntu1: fglrx-core kernel module failed to build [error: implicit declaration of function ‘__get_cpu_var’ ]

[ROCHE]

Trying to find a video driver working on ATI Radeon 4500 series on Ubuntu. Impossible to have a correct screen. Trying with AMD Radeon drivers on website AMD.
My pc : HP dv 2220 sf with ATI Radeon video 4500

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: fglrx-core 2:14.501-0ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-7.7-generic 3.19.0
Uname: Linux 3.19.0-7-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.16.1-0ubuntu2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
DKMSKernelVersion: 3.19.0-7-generic
Date: Fri Feb 27 19:05:22 2015
DistUpgraded: Fresh install
DistroCodename: vivid
DistroVariant: ubuntu
DuplicateSignature: dkms:fglrx-core:2:14.501-0ubuntu1:/var/lib/dkms/fglrx-core/14.501/build/2.6.x/firegl_public.c:4819:5: error: implicit declaration of function ‘__get_cpu_var’ [-Werror=implicit-function-declaration]
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] RV710/M92 [Mobility Radeon HD 4530/4570/545v] [1002:9553] (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Mobility Radeon HD 4530 [103c:3624]
InstallationDate: Installed on 2015-02-25 (1 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150224)
MachineType: Hewlett-Packard HP Pavilion dv7 Notebook PC
PackageVersion: 2:14.501-0ubuntu1
ProcKernelCmdLine: root=/dev/sda9 ro
Renderer: Software
SourcePackage: fglrx-installer
Title: fglrx-core 2:14.501-0ubuntu1: fglrx-core kernel module failed to build
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/25/2011
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: F.46
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 3624
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 18.51
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnHewlett-Packard:bvrF.46:bd08/25/2011:svnHewlett-Packard:pnHPPaviliondv7NotebookPC:pvrRev1:rvnHewlett-Packard:rn3624:rvr18.51:cvnHewlett-Packard:ct10:cvrN/A:
dmi.product.name: HP Pavilion dv7 Notebook PC
dmi.product.version: Rev 1
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.12.1+15.04.20150213-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.59-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.0~rc2-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.0~rc2-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.16.2.901-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.4.0-2ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2
xserver.bootTime: Fri Feb 27 18:48:37 2015
xserver.configfile: default
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.16.2.901-1ubuntu4

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Alessandro Viprati (vipri-alessandro)]

@ROCHE read this comment: https://bugs.launchpad.net/ubuntu/+source/fglrx-installer/+bug/1276379/comments/41
(and sorry for my poor english, I can't edit that comment and correct my errors).

However, it's the same for 15.04: you cannot install fglrx drivers because AMD dropped support for the Radeon HD 2xxx, 3xxx and 4xxx cards.
If you want to use proprietary drivers, they work only on Ubuntu 12.04.1 (kernel linux 3.2), but with an old version (Catalyst 13.1).

If you want to use Ubuntu 14.04 LTS or 15.04, you have to use the open Radeon drivers (preinstalled in Ubuntu).
Hope to help.