Hi, > -----Original Message----- > From: Moore, Robert > Sent: Tuesday, April 18, 2017 3:28 AM > To: 'Guenter Roeck' <linux@xxxxxxxxxxxx>; Zheng, Lv <lv.zheng@xxxxxxxxx> > Cc: Wysocki, Rafael J <rafael.j.wysocki@xxxxxxxxx>; 'Len Brown' <lenb@xxxxxxxxxx>; 'linux- > acpi@xxxxxxxxxxxxxxx' <linux-acpi@xxxxxxxxxxxxxxx>; 'devel@xxxxxxxxxx' <devel@xxxxxxxxxx>; 'linux- > kernel@xxxxxxxxxxxxxxx' <linux-kernel@xxxxxxxxxxxxxxx>; Box, David E <david.e.box@xxxxxxxxx> > Subject: RE: [PATCH] ACPICA: Export mutex functions > > > > -----Original Message----- > > From: Moore, Robert > > Sent: Monday, April 17, 2017 10:13 AM > > To: Guenter Roeck <linux@xxxxxxxxxxxx>; Zheng, Lv <lv.zheng@xxxxxxxxx> > > Cc: Wysocki, Rafael J <rafael.j.wysocki@xxxxxxxxx>; Len Brown > > <lenb@xxxxxxxxxx>; linux-acpi@xxxxxxxxxxxxxxx; devel@xxxxxxxxxx; linux- > > kernel@xxxxxxxxxxxxxxx > > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
