Re: APM crashes when IO is going on

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, 21 of March 2008, Mikulas Patocka wrote:
> Hi
> 
> > > > > I have an old notebook with APM and I am experiencing occasional APMD 
> > > > > lockups after resume, with kernels 2.6.25rc1 snd 2.6.25rc3. They didn't 
> > > > > happen with 2.6.24 or before.
> > > > > 
> > > > > The bug happens about once a week or so.
> > > > > 
> > > > > If you have any idea how to debug it, you can send me a test code.
> > > > 
> > > > It is possible that the bug was fixed in -rc4.  Can you please test -rc6 and
> > > > see if it's still present?
> > > > 
> > > > Thanks,
> > > > Rafael
> > > 
> > > I'm now running on -rc6, so I'll see (it takes some days for the bug to 
> > > appear). Where is that patch that went to -rc4 and that may fix it?
> > 
> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7a8d37a37380e2b1500592d40b7ec384dbebe7a0
> > 
> > Thanks,
> > Rafael
> 
> I found another problem --- present in 2.6.23.1, 2.6.25rc3, 2.6.25rc6
> 
> --- when I run three threads concurrently reading raw disk partition and 
> suspend, I get 100% reproducible failure. (with one thread running it 
> usually succeeds, sometimes fail)

Are they userland threads or kernel threads?

> Either the on-going I/O will jam BIOS and I need to remove power to 
> continue.
> 
> Or the machine suspends, wakes up and reports "hda: lost interrupt" 
> (2.6.23.1 was able to recover from this condition, 2.6.25rc3,6 does not 
> recover and it is not able to send any more disk IOs).
> 
> How is suspending disk IO supposed to work?

That depends on the driver, if I understand your question correctly.

> And why it doesn't?

Hard to tell.  You didn't provide much information ...

Thanks,
Rafael