Here is a fresh summary (with one new result) of the problem on
machines
with integrated Intel graphics in which Adobe Flash Player 11.2
displays
only with shades of purple and green in a horizontally compressed
window.
(My current example is a Dell Dimension 2400 on Raring.)
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 kernel **
- 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 Saucy 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 on file at
http://bugs.launchpad.net/ubuntu/+source/linux/+bug/1178982. (Note that
it was filed against Linux.) 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.
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** Flash sort of works in this case. The colors and window dimensions
are normal. But there were other odd display-related effects. Raring
booting to a a low-resolution desktop with the mouse pointer locked. I
started Chromium via the keyboard and the flash video played long
enough
for me to see normal colors/dimensions, but then it locked up the
browser.
In my interest in testing under Raring with an older kernel, I
initially
tried to use a Live USB with persistence and follow the instructions at
https://wiki.ubuntu.com/Kernel/MainlineBuilds for installing older
Mainline kernels. But this failed to install/run properly with the
Live
USB. And besides, I wanted to use Stock rather than Mainline kernels.
So I installed a different hard drive, installed Quantal, then upgraded
to Raring. I suppose if I had run Software Update under Quantal, I
would have gotten a 3.6 kernel to test as well. As it was, Raring's
Software Update did not install a 3.6 kernel, but only the kernel
updates proper to Raring.
------------------------------------------------------------------------
Looking at the above behavior of the "black box" without nearly enough
technical knowledge, all I can see at this point is that there is an
adverse interplay between certain versions of the kernel, the Intel
driver, and Flash. (And I grant that I have not documented the
versions
of the Intel driver in the various cases, but no one has given me any
indication that the Intel driver version is an issue here.)
