panic in AcpiExReleaseMutex

[Moore, Robert]

>This  thread has a fixed tid of 100000.

This is ok.

Well, I don't see anything obvious. You will probably need to step through the calls to AcpiExAcquireMutex and AcpiExReleaseMutex, or at least add some printfs to monitor the value of WalkState->Thread->AcquiredMutexList.


Another question, however: is the global lock involved in any way?


>-----Original Message-----
>From: Andriy Gapon [mailto:avg at icyb.net.ua]
>Sent: Friday, December 04, 2009 1:20 PM
>To: Moore, Robert
>Cc: freebsd-acpi at freebsd.org; Tarick
>Subject: Re: panic in AcpiExReleaseMutex
>
>on 04/12/2009 22:59 Moore, Robert said the following:
>> It would appear that a GPE is taken, for the EC device, thus invoking
>> EcGpeQueryHandler. In what context is _Q20 or _Q09 executed?
>
>It's invoked in "polling mode" at that stage.  Interrupts are not enabled
>yet at
>that point.  Let me quote my original report:
>[quote]
>_REG method seems to access some registers in EC address space (with
>\_SB.PCI0.LPC0.EC0.MUT1 mutex locked).  That access triggers a call to
>EcSpaceHandler.  Now, we have a code in EcSpaceHandler that makes a direct
>call
>to EcGpeQueryHandler during a cold boot phase if SCI bit is set in CSR
>register.
>EcGpeQueryHandler performs an EC query and executes _Qxx method if need.
>[/quote]
>
>So, everything happens in the same thread with the same context and stack.
>
>> This might be an important question: What is the thread_id of this
>initial
>> thread?
>
>This  thread has a fixed tid of 100000.
>
>>> -----Original Message----- From: Andriy Gapon [mailto:avg at icyb.net.ua]
>>> Sent: Friday, December 04, 2009 12:50 PM To: Moore, Robert Cc:
>>> freebsd-acpi at freebsd.org; Tarick Subject: Re: panic in
>AcpiExReleaseMutex
>>>
>>> on 04/12/2009 20:45 Moore, Robert said the following:
>>>> Yes, you are correct. I did not have the code in front of me at the
>time.
>>>>
>>>>
>>>>
>>>>
>>>> When AcpiExReleaseMutex is called, apparently the mutex is in fact
>held,
>>>> otherwise the function would have aborted immediately.
>>>>
>>>> When the mutex is held, the Thread->AcquiredMutexList is expected to
>hold
>>>>
>>>>
>>>>
>>> (at
>>>> the minimum) the mutex object being released. Something is very wrong
>if
>>> this
>>>> list is NULL when releasing the mutex.
>>>>
>>>> Just to make sure: All of this is happening in the same thread?
>>> Yes, this happens when there is only the initial thread running on BSP,
>no
>>> other threads are started yet.
>>>
>>>
>>> -- Andriy Gapon
>
>
>--
>Andriy Gapon