Sandy Bridge X crash - OpenGL/DPMS-related?

[Ian Pilcher <arequipeno@gmail.com>]

Fedora 15 Alpha on a brand new Sandy Bridge system (Core i7 2600 with
"Intel HD" graphics).  Running KDE and using GLMatrix screensaver.

When I unlocked the system this morning, the password entry dialog
was not displayed correctly.  When I pressed a key, only the password
entry field became visible.  The "Switch User ...", "Unlock", and
"Cancel" buttons only appeared when I moved the mouse pointer over
them; the dialog background remained black.

When I entered my password, X crashed.  The backtrace in the log is:

Backtrace:
[ 49562.907] 0: /usr/bin/X (xorg_backtrace+0x2f) [0x4a117f]
[ 49562.907] 1: /usr/bin/X (0x400000+0x621c6) [0x4621c6]
[ 49562.907] 2: /lib64/libpthread.so.0 (0x37ae800000+0xf4e0) [0x37ae80f4e0]
[ 49562.907] 3: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x84251)
[0x7fd70c43d251]
[ 49562.907] 4: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x6e116)
[0x7fd70c427116]
[ 49562.907] 5: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x5d5cd)
[0x7fd70c4165cd]
[ 49562.907] 6: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x148b93)
[0x7fd70c501b93]
[ 49562.907] 7: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x14690c)
[0x7fd70c4ff90c]
[ 49562.907] 8: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x146b0a)
[0x7fd70c4ffb0a]
[ 49562.907] 9: /usr/lib64/dri/i965_dri.so (0x7fd70c3b9000+0x1090cb)
[0x7fd70c4c20cb]
[ 49562.907] 10: /usr/lib64/xorg/modules/extensions/libglx.so
(0x7fd70d839000+0x310b9) [0x7fd70d86a0b9]
[ 49562.907] 11: /usr/lib64/xorg/modules/extensions/libglx.so
(0x7fd70d839000+0x33831) [0x7fd70d86c831]
[ 49562.907] 12: /usr/bin/X (0x400000+0x2ebd1) [0x42ebd1]
[ 49562.907] 13: /usr/bin/X (0x400000+0x22e5a) [0x422e5a]
[ 49562.907] 14: /lib64/libc.so.6 (__libc_start_main+0xed) [0x37adc2131d]
[ 49562.907] 15: /usr/bin/X (0x400000+0x23141) [0x423141]
[ 49562.907] Segmentation fault at address (nil)
[ 49562.907]
Fatal server error:
[ 49562.907] Caught signal 11 (Segmentation fault). Server aborting

(I have installed the relevant debuginfo packages and reproduced the
crash, but the backtrace in the X.org log doesn't appear to be using
those symbols.  Any way I can get a more useful backtrace?)

Based on my attempts to reproduce the crash, it appears to be DPMS-
related.  Unlocking the screensaver before DPMS turns off my displays
works just fine.  (The unlock dialog is displayed correctly, and X
doesn't crash.)  If I let the screensaver run until the displays are
powered down, the unlock dialog is display incorrectly and X crashes
when I enter my password and press enter.

Any ideas?

Thanks!

-- 
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Ian Pilcher                                         arequipeno@gmail.com
"If you're going to shift my paradigm ... at least buy me dinner first."
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