1002:9830 [Lenovo Ideapad S415 Touch] Screen corruption in Firefox via Radeon

[penalvch]

I get intermittent screen corruption in Firefox using the Radeon driver. It's typically a character here and there, once every few minutes. A screenshot of this is attached.

WORKAROUND: While the fglrx driver doesn't exhibit this exact problem, I get heavy screen corruption when having a lot of different flash based videos play simultaneously in chromium.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xorg 1:7.7+1ubuntu8
ProcVersionSignature: Ubuntu 3.13.0-35.62-generic 3.13.11.6
Uname: Linux 3.13.0-35-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.4
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
CurrentDesktop: Unity
Date: Wed Sep 24 05:41:20 2014
DistUpgraded: Fresh install
DistroCodename: trusty
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] Kabini [Radeon HD 8400] [1002:9830] (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:3802]
InstallationDate: Installed on 2014-06-21 (94 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: LENOVO 20319
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-35-generic.efi.signed root=UUID=a2db89ed-d599-4138-8838-0b950b6c3fbb ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/14/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 8CCN29WW(V2.03)
dmi.board.asset.tag: No Asset Tag
dmi.board.name: Lenovo IdeaPad S415 Touch
dmi.board.vendor: LENOVO
dmi.board.version: 31900058Std
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad S415 Touch
dmi.modalias: dmi:bvnLENOVO:bvr8CCN29WW(V2.03):bd11/14/2013:svnLENOVO:pn20319:pvrLenovoIdeaPadS415Touch:rvnLENOVO:rnLenovoIdeaPadS415Touch:rvr31900058Std:cvnLENOVO:ct10:cvrLenovoIdeaPadS415Touch:
dmi.product.name: 20319
dmi.product.version: Lenovo IdeaPad S415 Touch
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.11.2+14.04.20140714-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.3-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.3-0ubuntu0.1
version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3.1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Mon Sep 22 22:28:04 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.15.1-0ubuntu2.1
xserver.video_driver: radeon

[penalvch (penalvch)]

Still happens after upgrading to linux-generic-lts-utopic stack in Trusty, and BIOS update:
uname -a
Linux monikerpc 3.16.0-28-generic #37-Ubuntu SMP Tue Dec 9 11:06:13 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
8CCN34WW(V3.04)
10/14/2014

[penalvch (penalvch)]

Upgraded to Vivid+, haven't seen the problem since.