Re: [PATCH] kthread conversion: convert ieee1394 from kernel_thread
From: Stefan Richter
Date: Sun Jun 18 2006 - 06:28:58 EST
I wrote:
I will try to rework this patch
While doing so I discovered an old bug which happens with current code
as well as with Linux 2.6.16.x and 2.6.15.x, maybe also on older kernels:
When "modprobe ohci1394" is followed shortly by "modprobe -r ohci1394"
(say, 1 second after the previous modprobe finished), one of the
following may happen:
- kernel panic due to exception in interrupt
(happened on 2.6.15.x preempt uniprocessor)
or
- modprobe -r hangs in D state, as does knodemgrd_0
(happened on 2.6.16.x preempt SMP on a uniprocessor machine).
I have two FireWirew host adapters installed. The knodemgrd_1 slept
interruptibly (S state) while the other slept uninterruptibly (D state)
right after modprobe -r was issued. This happens with or without other
nodes attached to the FireWire ports. Host adapters are based on a TI
1394b chip (host 0) and on a VIA 1394a chip (host 1).
"All's right with the world" if a longer pause is put between modprobe
and modprobe -r, say 4 seconds.
(I will add a bugzilla entry and try to resolve this eventually...)
--
Stefan Richter
-=====-=-==- -==- =--=-
http://arcgraph.de/sr/
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