i915 DRM problems in lucid.

[Robert Hooker]

Hello, I've found a lot of bug fixes for i915 that seem needed in the
lucid kernel and I thought I'd list them here for consideration since
I'm not having any luck in IRC.


* GPU hangs after DPMS events
*Quite* a lot of reports of this bug, the fix was included in
2.6.32-15 but was dropped during the 2.6.33 DRM merge that happened in
2.6.32-16. Due to the number of people it affects it seems pretty
urgent to bring this back in. Symptoms include hangs after lid close,
idle screen blanking, and suspend/resume. dmesg and old xorg/gdm logs
will show batchbuffer I/O errors when it crashed, EIR is always
00000000 and it eventually ends up with an assert like this happening
- X: ../../src/i830_batchbuffer.h:79: intel_batch_emit_dword:
Assertion `pI830->batch_ptr != ((void *)0)' failed.

Bug: https://launchpad.net/bugs/535640
Fix: http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-lucid.git;a=commit;h=7b56712ff524ee55e38afaee3954d125f56a6070


* Framebuffer compression causing rendering to stop on 915 and 945
mobile devices after resume.
This one was brought up on the list previously, but it is pretty nasty
and affects all mobile 915-945 users. I submitted my patch upstream
and they applied it and I will send it to stable once it's in linus'
tree but that will probably be awhile with how rarely the intel tree
is pulled in lately.

Bug: https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/492392
Fix: https://patchwork.kernel.org/patch/86999/


* i915 module getting loaded before agpgart
This has been an issue since karmic at least, and is also happening
with radeon. Intel has fixed this in 2.6.34 but it hasn't been
backported to stable yet. This especially seems like a backport worth
considering due to how fast boots are now. Side note about this:
upstream might even actually require AGP modules to be built into the
kernel at some point, the consensus seems to be module AGP=bad.

Bug: https://bugs.launchpad.net/bugs/542251
Fix: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1f7a6e372e9cb4d749f34c0738d832e6cadb4071


* Large number of reports requiring lid quirks
Upstream has decided to drop the requirement of having a lid open
status to enable the LVDS completely because a large number of quirks
were getting sent, a lot of manufacturers screw this up because
Windows/OSX don't require it.

Fix: http://git.kernel.org/?p=linux/kernel/git/anholt/drm-intel.git;a=commit;h=6e6c822868f113dabe3c33bdd91e883cc28fa11b