kernel trap with ACPI on 4.10-release

[Moore, Robert]

29 October 2003.  Summary of changes for version 20031029:

...


Updated the implementation of the Stall() operator to only call
AcpiOsStall(), and also return an error if the operand is larger than
255.  This preserves the required behavior of not relinquishing the
processor, as would happen if AcpiOsSleep() was called for "long
stalls".


> -----Original Message-----
> From: Moore, Robert
> Sent: Friday, June 18, 2004 7:43 AM
> To: 'Andriy Gapon'; freebsd-acpi at freebsd.org
> Subject: RE: kernel trap with ACPI on 4.10-release
> 
> This has been fixed for some number of months.  What version of ACPI
CA
> are you using?
> Bob
> 
> 
> > -----Original Message-----
> > From: owner-freebsd-acpi at freebsd.org [mailto:owner-freebsd-
> > acpi at freebsd.org] On Behalf Of Andriy Gapon
> > Sent: Friday, June 18, 2004 6:50 AM
> > To: freebsd-acpi at freebsd.org
> > Subject: Re: kernel trap with ACPI on 4.10-release
> >
> > on 11.06.2004 15:20 Andriy Gapon said the following:
> > >
> > ...
> > > Having no knowledge in ACPI internals and very little knowledge in
> > > kernel internals I can not dare suggest what would be most
appropriate
> > > to do. Nevertheless, it seems that (1) would be too intrusive and
> > > global; (3) is complex and might not be too reliable; (2) seems to
be
> > > the easiest, one line change from "taskqueue_swi" to
> "taskqueue_thread"
> > > in OsdSchedule.c
> > >
> > > I hope my investigation has something helpful in it, and any
feedback
> > > would also be very helpful for my self-education on kernel
matters.
> >
> > I looked into the problem more carefully and thoughtfully and now I
> > understand that I was looking in a completely wrong place for a
> > completely wrong stuff.
> > There should not have been any parallel execution thanks to proper
> > splhigh() locking, *but there was*! And I think I know why. I added
some
> > debugging printf-s and determined that tasks on taskqueue_swi were
> > executed while acpi_tz_thread "held" splhigh(), this led me to idea
that
> > this kernel thread somewhere willingfully gave up its priority, like
in
> > tsleep().
> > In my DSTD _TMP() accesses Winbond HWM chip to read current
temperature
> > and its access routine has calls to Stall(). If I understand Intel
> > ACPICA code correctly this call is executed in AcpiExSystemDoStall()
> > function (/usr/src/sys/contrib/dev/acpica/exsystem.c).
> > Looking at the code present in 4.10 (file revision 75) it seems that
it
> > is entirely backwards: it calls AcpiOsStall() for long delays and
> > AcpiOsSleep() for short delays, also incorrectly converts units for
the
> > latter case, not speaking of the fact that ACPI standard commands
that
> > Stall should not be used for delays longer than 100 microseconds and
CPU
> > should not be given up.
> > I see that this function was made sane in the code imported in
CURRENT
> > (file revision 80). I realize that this is a contributed, vendor
code,
> > but I think AcpiExSystemDoStall() should be patched for STABLE too,
> > because the way it is now, it is outright buggy and dangerous.
> >
> > --
> > Andriy Gapon
> > _______________________________________________
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