Re: [PATCH] ACPICA: Export mutex functions

Rafael J. Wysocki
2017-04-14T22:36:17Z

On Wednesday, April 12, 2017 09:56:37 PM Moore, Robert wrote:
>
> > -----Original Message-----
> > From: Guenter Roeck [mailto:linux@roeck-us.net]
> > Sent: Wednesday, April 12, 2017 2:23 PM
> > To: Moore, Robert <robert.moore@intel.com>
> > Cc: Zheng, Lv <lv.zheng@intel.com>; 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
> >
> > On Wed, Apr 12, 2017 at 03:29:55PM +0000, Moore, Robert wrote:
> > > The ACPICA mutex functions are based on the host OS functions, so they
> > don't really buy you anything. You should just use the native Linux
> > functions.
> > >
> >
> > You mean they don't really acquire the requested ACPI mutex, and the
> > underlying DSDT which declares and uses the mutex just ignores if the
> > mutex was acquired by acpi_acquire_mutex() ?
> >
> [Moore, Robert]
>
> OK, I understand now. Yes, these mutex interfaces are in fact intended for the purpose you mention:
>
> * FUNCTION: AcpiAcquireMutex
> *
> * PARAMETERS: Handle - Mutex or prefix handle (optional)
> * Pathname - Mutex pathname (optional)
> * Timeout - Max time to wait for the lock (millisec)
> *
> * RETURN: Status
> *
> * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to
> * AML mutex objects, and allows for transaction locking between
> * drivers and AML code. The mutex node is pointed to by
> * Handle:Pathname. Either Handle or Pathname can be NULL, but
> * not both.
>
>
> And yes, both the acquire and release interfaces should be exported.

OK, so I'm assuming this will go in through the upstream ACPICA.

Thanks,
Rafael