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[Bug 682864] Re: [GMA 4500MHD] Display freeze after VGA cable disconnected

 

Hi,

Thanks for reporting this X gpu lockup bug in Ubuntu maverick.

In my opinion GPU lockups are one of the most frustrating kinds of bugs,
both as a user and a developer.  I want take a few moments of your time
to explain the situation with these types of bugs.

For some reason, -intel has been plagued with these freeze bugs for a
long time.  In the past -intel has had options to switch to legacy
memory or rendering technologies as workarounds, but Intel tends to drop
obsolete code pretty aggressively and unfortunately in maverick these
workarounds are not available.

As a policy, Intel engineers look only at bugs that are seen in the most
recent release of their drivers.  With older versions of their drivers,
such as the version in maverick, we're on our own.

On the plus side, they provide good tools for gathering debug data about
the bugs, such as the intel_gpu_dump too.  Unfortunately, the version of
Apport in maverick doesn't capture the dmesg or X logs correctly (it
collects the files at the time of freeze, but then overwrites them with
clean, unhelpful versions when it goes to file the report for you.)

The version of these diagnostic tools in natty has been fixed up, and is
allowing us to analyze GPU lockups a lot easier.  This has helped us
solve several of the bugs, and given us a handle on some of the more
challenging ones.

Backporting these fixes may not be feasible though; by their nature the
fixes for these type of bugs tend to be very low level, esoteric, and
risky of causing something else to regress.  Because the freezes are
often hard to reproduce, it's not always possible to verify fixes
anyway.  It may be that our best bet is to focus on natty.

But for now, since these freezes typically require kernel patches to
solve, I'm moving your bug report to the kernel package.  They may be
able to point you to a newer kernel likely to help with this issue.

** Package changed: xserver-xorg-video-intel (Ubuntu) => linux (Ubuntu)

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https://bugs.launchpad.net/bugs/682864

Title:
  [GMA 4500MHD] Display freeze after VGA cable disconnected



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