Comment 0 for bug 1212455

The issue seems related to the Intel (845G) integrated graphics. I have not seen the behavior on other hardware.

In my testing with the Intel driver using its default acceleration:
- Flash 11.2 works on Quantal with the 3.5 kernel
- Flash 11.2 works on Raring with the 3.5.0-17 kernel (though it boots to a low-res desktop with a frozen pointer)
- Flash 11.2 works on Raring also with the 3.6.11-030611 or 3.7.10-030710 mainline kernels
- Flash 11.8 works on Raring with the 3.8 kernel (in Chrome)
- Flash 11.2 fails on Raring with the 3.8 kernel
- Flash 11.2 fails on Raring with the latest mainline kernel, 3.11.0-031100rc5
- Flash 11.2 fails on Saucy alpha 2 with its default kernel

Disabling Flash *hardware* acceleration altogether (via R-click in the Flash display window: Settings: General tab) did not fix the problem.

Setting the Intel driver's acceleration method to UXA rather than its default SNA *always* fixes the Flash problem, but causes a garbled login screen under LightDM that so far has no workaround.

I also tried one possible fix for the default Intel SNA acceleration using the TearFree option. I created /etc/X11/xorg.conf.d/20-intel.conf with contents:
    Section "Device"
       Identifier "Intel Graphics"
       Driver "intel"
       Option "AccelMethod" "sna"
       Option "TearFree" "true"
    EndSection
But this had no effect.

There was a helpful bug report file against Linux at http://bugs.launchpad.net/ubuntu/+source/linux/+bug/1178982. Workarounds posted there were to change the Xorg acceleration method to UXA, or boot with an older kernel. The bug was closed only because the original poster didn't have possession of the machine anymore.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: linux-image-3.8.0-27-generic 3.8.0-27.40
ProcVersionSignature: Ubuntu 3.8.0-27.40-generic 3.8.13.4
Uname: Linux 3.8.0-27-generic i686
ApportVersion: 2.9.2-0ubuntu8.3
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: user1 1467 F.... lxpanel
CRDA: Error: [Errno 2] No such file or directory: 'iw'
CurrentDmesg:
 [ 72.390428] serial8250: too much work for irq17
 [ 72.401696] serial8250: too much work for irq17
 [ 72.411724] serial8250: too much work for irq17
 [ 82.046726] serial8250: too much work for irq17
Date: Wed Aug 14 17:39:10 2013
HibernationDevice: RESUME=UUID=8adf1633-c1a8-4392-8fc3-44369bc85692
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.
Lsusb:
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: Dell Computer Corporation Dimension 2400
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-27-generic root=UUID=a41f2f68-7642-46f9-88d8-08a656c1c40d ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.8.0-27-generic N/A
 linux-backports-modules-3.8.0-27-generic N/A
 linux-firmware 1.106
RfKill:

SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/02/2003
dmi.bios.vendor: Dell Computer Corporation
dmi.bios.version: A05
dmi.board.name: 0F5949
dmi.board.vendor: Dell Computer Corp.
dmi.board.version: A01
dmi.chassis.type: 15
dmi.chassis.vendor: Dell Computer Corporation
dmi.modalias: dmi:bvnDellComputerCorporation:bvrA05:bd12/02/2003:svnDellComputerCorporation:pnDimension2400:pvr:rvnDellComputerCorp.:rn0F5949:rvrA01:cvnDellComputerCorporation:ct15:cvr:
dmi.product.name: Dimension 2400
dmi.sys.vendor: Dell Computer Corporation