Hi, > -----Original Message----- > From: Moore, Robert > Sent: Tuesday, April 18, 2017 3:28 AM > To: 'Guenter Roeck' <li...@roeck-us.net>; Zheng, Lv <lv.zh...@intel.com> > Cc: Wysocki, Rafael J <rafael.j.wyso...@intel.com>; 'Len Brown' > <l...@kernel.org>; 'linux- > a...@vger.kernel.org' <linux-a...@vger.kernel.org>; 'de...@acpica.org' > <de...@acpica.org>; 'linux- > ker...@vger.kernel.org' <linux-kernel@vger.kernel.org>; Box, David E > <david.e....@intel.com> > Subject: RE: [PATCH] ACPICA: Export mutex functions > > > > -----Original Message----- > > From: Moore, Robert > > Sent: Monday, April 17, 2017 10:13 AM > > To: Guenter Roeck <li...@roeck-us.net>; Zheng, Lv <lv.zh...@intel.com> > > Cc: Wysocki, Rafael J <rafael.j.wyso...@intel.com>; Len Brown > > <l...@kernel.org>; linux-a...@vger.kernel.org; de...@acpica.org; linux- > > ker...@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.
That sounds reasonable but the driver might invoke an ACPICA API accessing the _DLM returned mutexes. Thanks and best regards Lv
