suspend/resume garbles ATI Radeon screen (but not screenshots)

Suspend/resume garbles the screen (both X and VTs) by consistently shifting pixels, producing a wierd emboldening effect and color shadows.

Using AT Radeon graphics card and large (1920 x 1280) monitor, with the standard FREE driver (not fglrx).

Taking a screen-shot produces an unaffected image (does not exhibit the corruption). So the bug may have to do with some rendering settings in the hardware, rather than actually corrupted display memory (just speculation). The problem never occurs after a normal boot, only after resume.

The problem does not always occur (but usually does). So it there may be some memory or hw register not being initialized.

I will attach cellphone photos showing the corrupted screen (as mentioned above, a screenshot does not show the problem).

Note: This is an old problem. In Ubuntu 9.10 I used fglrx and the problem would occur somewhat less frequently, and when it did the VTs were not affected, and switching to a VT and back to X fixed the corruption. But int 10.04 VTs are affected also and switching does not help.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-image (not installed)
Regression: No
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.32-23.37-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-23-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: jima 1529 F.... pulseaudio
 /dev/snd/pcmC0D0p: jima 1529 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfbaf8000 irq 22'
   Mixer name : 'Realtek ALC1200'
   Components : 'HDA:10ec0888,104383c0,00100101'
   Controls : 35
   Simple ctrls : 20
Card1.Amixer.info:
 Card hw:1 'HDMI'/'HDA ATI HDMI at 0xfbbfc000 irq 34'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100000'
   Controls : 4
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [off]
Date: Fri Aug 6 23:26:10 2010
HibernationDevice: RESUME=UUID=cb241bc2-3850-4161-898f-caa64bf877da
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.

 vboxnet0 no wireless extensions.
MachineType: System manufacturer System Product Name
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-23-generic root=UUID=6ac6f5f8-5733-4d3e-878a-c901d4847ce7 ro quiet splash
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.34.1
RfKill:

SourcePackage: linux
dmi.bios.date: 12/30/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1004
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P6T
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1004:bd12/30/2009:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP6T:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer