RE: [PATCH] ACPICA: Export mutex functions

Moore, Robert
2017-04-17T19:27:50Z

> -----Original Message-----
> From: Moore, Robert
> Sent: Monday, April 17, 2017 10:13 AM
> To: Guenter Roeck <linux@roeck-us.net>; Zheng, Lv <lv.zheng@intel.com>
> Cc: Wysocki, Rafael J <rafael.j.wysocki@intel.com>; Len Brown
> <lenb@kernel.org>; linux-acpi@vger.kernel.org; devel@acpica.org; linux-
> kernel@vger.kernel.org
> Subject: RE: [PATCH] ACPICA: Export mutex functions
>
> There is a model for the drivers to directly acquire an AML mutex
> object. That is why the acquire/release public interfaces were added to
> ACPICA.
>
> I forget all of the details, but the model was developed with MS and
> others during the ACPI 6.0 timeframe.
>
>
[Moore, Robert]

Here is the case where the OS may need to directly acquire an AML mutex:

>From the ACPI spec:

19.6.2 Acquire (Acquire a Mutex)

Note: For Mutex objects referenced by a _DLM object, the host OS may also contend for ownership.

Other than this case, the OS/drivers should never need to directly acquire an AML mutex.
Bob