RE: Method execution failed

A later version of acpi fixed the init_globals issue, static init only
for the runtime options

-----Original Message-----
From: Alex Williamson [mailto:alex.williamson-VXdhtT5mjnY@public.gmane.org]
Sent: Friday, August 06, 2004 10:27 AM
To: Moore, Robert
Cc: acpi-devel
Subject: RE: [ACPI] Method execution failed

On Fri, 2004-08-06 at 10:07 -0700, Moore, Robert wrote:

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This is a bug in the ASL/AML for this machine.  Methods that are
declared "NotSerialized" are forbidden from creating objects within

the

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namespace (or at least forbidden from creating names that will

clash).

  Argh, I'll bug our firmware guys it that's the problem.

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There is a fix to the ACPI code that detects this problem and

changes

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"NotSerialized" to "Serialized" on the fly.  There is also a runtime
option to force all control methods to be "Serialized".

   I tried adding acpi_serialize to my boot options, I see "ACPI:
serialize enabled" in dmesg.  However, it still breaks when calling
methods concurrently.  Looks like acpi_ut_init_globals() is likely
reseting later on.  How do I enable the on-the-fly checking?  Thanks

for

the quick response!

	Alex

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-----Original Message-----
From: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org [mailto:acpi-devel-
admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] On Behalf Of Alex Williamson
Sent: Friday, August 06, 2004 9:48 AM
To: acpi-devel
Subject: [ACPI] Method execution failed


   I think there's a locking issue w/ namespace for concurrent

calls

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to

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acpi_evaluate_object().  FWIW, these concurrent calls are coming

in

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through my acpi sysfs patch, so it could be a bug in that code.

If I

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serialize calls into acpi_evaluate_object(), it works fine, but I

don't

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see a global lock for this, so I think the problem is more

general.

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If

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I make lots of calls to evaluate the same _BBN object, I start

seeing

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these:

ACPI-0279: *** Error: Looking up [LBAS] in namespace,

AE_ALREADY_EXISTS

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ACPI-1133: *** Error: Method execution failed [\LBA_.BBN_] (Node
e00000407fd

This starts at acpi_ds_load1_begin_op() doing a path lookup,

presumably

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expecting not to find the path with flag ACPI_NS_ERROR_IF_FOUND.

The

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AML for the method is:

0000000: a45c 2e4c 4241 5f42 424e 5f5e 5f55 4944  .\.LBA_BBN_^_UID

The first part of the _SB/LBA/BBN_ AML looks like this:

0000000: 084c 4241 5311 030a 408a 4c42 4153 0056  .LBAS...@.LBAS.V
0000010: 414c 448a 4c42 4153 0a04 4c46 4c47 8a4c  ALD.LBAS..LFLG.L
...

The LBA/BBN_ method appears to make an object named LBAS.  When

calling

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this multiple times, each instance wants to not find this object

and

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then create it.  However, the namespace lock is given up around

method

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execution, so it seems we have some races.  Am I completely mis-
interpreting the problem, or does this sound plausible?  I don't

really

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know how to read AML, so this is just a guess.  Do we need to be

more

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stringent on locking namespace, or is there a bug in the AML I'm
calling?  Thanks,

	Alex

--
Alex Williamson                             HP Linux & Open Source

Lab

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--
Alex Williamson                             HP Linux & Open Source Lab

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