USB detach/attach hangs with 7.0-RELEASE and 7.1-PRERELEASE
Bruce M Simpson
bms at incunabulum.net
Mon Sep 29 00:46:17 UTC 2008
I've noticed some general instability with plugging in or removing USB
devices with FreeBSD 7.x, even when the devices are not actively in use.
I had this happen with umass and ucom devices 3 times today. The machine
hangs solid, there are no obvious signs of a panic or trap to DDB. I
can't provide backtraces unfortunately -- these hangs happen on both my
laptop and desktop, and I usually have X running -- if I had more
specific information, I'd open a PR.
Again, there seems to be no reason why this should happen, the devices
are off-the-shelf consumer items known to work with existing drivers,
and have been repeatedly used in other OSes without these hangs
happening; consider this an "anecdotal report".
[For some reason my IBM laptop will often not allow me to break into DDB
on a driver related panic, and will just immediately reboot -- I lack
free time to track down exactly why this could be.
My desktop has a USB keyboard and this appears not to be supported by
DDB, I ordered a PS/2 keyboard which hasn't arrived, but that's another
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