[AMD Trinity + Thames]: Failed to resume from suspend

System with open source driver unable to resume correctly after suspend.

As a verify manually install fglrx driver, resume from suspend is okay. However is not recommended in "Additional Drivers", bug reported sperately here: bug 1390338

Graphic Chipsets:
ubuntu@201209-11726:/usr/lib/checkbox/bin$ lspci -nn|grep -i VGA
00:01.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Trinity [Radeon HD 7520G] [1002:9990]
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Thames [Radeon HD 7500M/7600M Series] [1002:6840] (rev ff)

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.13.0-43-generic 3.13.0-43.72~precise1
ProcVersionSignature: Ubuntu 3.13.0-43.72~precise1-generic 3.13.11.11
Uname: Linux 3.13.0-43-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.13.0-43-generic.
ApportVersion: 2.0.1-0ubuntu17.8
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 1: Generic [HD-Audio Generic], device 0: 92HD87B2/4 Analog [92HD87B2/4 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: ubuntu 1852 F.... pulseaudio
 /dev/snd/controlC0: ubuntu 1852 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'HDMI'/'HDA ATI HDMI at 0xf0444000 irq 51'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100300'
   Controls : 7
   Simple ctrls : 1
Card0.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Card1.Amixer.info:
 Card hw:1 'Generic'/'HD-Audio Generic at 0xf0440000 irq 16'
   Mixer name : 'IDT 92HD87B2/4'
   Components : 'HDA:111d76d9,103c184c,00100107'
   Controls : 23
   Simple ctrls : 11
Date: Mon Jan 12 01:54:51 2015
HibernationDevice: RESUME=UUID=59dbefd6-0f07-4ab2-b39c-158e22572e02
InstallationMedia: Ubuntu 12.04.5 LTS "Precise Pangolin" - Release amd64 (20140807.1)
MachineType: Hewlett-Packard HP Pavilion g7 Notebook PC
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB:
 0 radeondrmfb
 1 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-43-generic root=UUID=3a89e214-edc2-4888-9967-9dcfc27af6ad ro quiet splash initcall_debug vt.handoff=7
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory /home/ubuntu not ours.
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-43-generic N/A
 linux-backports-modules-3.13.0-43-generic N/A
 linux-firmware 1.79.18
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux-lts-trusty
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/17/2012
dmi.bios.vendor: Insyde
dmi.bios.version: F.21
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 184C
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 57.34
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnInsyde:bvrF.21:bd10/17/2012:svnHewlett-Packard:pnHPPaviliong7NotebookPC:pvr089D110000005010000020100:rvnHewlett-Packard:rn184C:rvr57.34:cvnHewlett-Packard:ct10:cvrChassisVersion:
dmi.product.name: HP Pavilion g7 Notebook PC
dmi.product.version: 089D110000005010000020100
dmi.sys.vendor: Hewlett-Packard