Enabling MCA causes system hangs

Daniel O'Connor doconnor at gsoft.com.au
Fri Sep 10 02:36:49 UTC 2010

I recently tried enabling MCA (ie w.mca.enabled=1 in loader.conf) on an 8.0-STABLE system and found that it would cause the system to hang after a few minutes of uptime.

The screen would go black and the monitor would turn off (regardless of wether it was in X or not) and only a hard reset would bring it back.

Also I found that quite often I had to power cycle the whole PC or the BIOS wouldn't detect the hard disks on boot(!) after a hang.

uname is..
FreeBSD midget.dons.net.au 8.0-STABLE FreeBSD 8.0-STABLE #6 r202903M: Sun Jan 24 13:45:11 CST 2010     darius at midget.dons.net.au:/usr/obj/usr/src/sys/MIDGET  amd64

The motherboard is a Gigabyte GA-MA785GM-US2H with an Athlon II X2 240 CPU & 4Gb of RAM.

Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
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