Deep sleep modes on 7-BETA locks up syscons

[Kevin Oberman]

I have already sent much of this to -current@, but ACPI is clearly
involved and I'll admit that I don't fully understand all of the
implications of sleep (Cx) states.

Recently I discovered that I could no longer boot up on battery. (As it
turned out, I could not shut down, either.) The boot proceeds to devd
which kicks off power_profile which resets the cx_state. I use
performance_cx_lowest="HIGH" and economy_cx_lowest="LOW" which drops
cx_state to C4 when on battery. 

States of C1 and C2 don't cause a problem and C3 and C4 do. (C4 is only
available when on battery.)

At that point things slow to a crawl. I have never had the patience to
see if it would ever finish the boot, but it took many minutes just to
start ipfw and load the rules. When anything made it to the screen, it
appeared several lines at a time.

If I am up and switch cx_state to C3 or C4 while running X, things work
fine, but, if I exit X while the cx_state is still C3 or C4, the system
switches back to the vty and spits out a few lines before locking up
again. After several minutes I was able to log in to another vty and
change the cx_state which started things running normally.

This is a T43 (Pentium-M @2GHz) running ULE on 7-BETA2 of Nov. 4. The
problem has not been there for too long, but I can't say for sure when I
last ran on battery when not in X. 

I don't know if this is a syscons issue or some ugly interaction between
syscons and ULE or an ACPI issue.

If anyone else has seen this or has any ideas, I'd love to hear about it.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751
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