RE: [PATCH v2 5/5] ACPICA: Remove deprecated _LINUX definitions for ACPICA.

[Zheng, Lv]

Hi, Rafael

> From: Rafael J. Wysocki [mailto:rjw@xxxxxxxxxxxxx]
> Sent: Monday, April 28, 2014 5:39 AM
> 
> On Wednesday, April 23, 2014 02:54:22 PM Lv Zheng wrote:
> > There are _LINUX defined so that when Linux kernel is compiled using broken
> > compilers that having not __linux__ defined can still include
> > <acpi/platform/aclinux.h> from <acpi/platform/acenv.h>.
> >
> > This behavior is deprecated as all drivers/acpi/acpica files are compiled
> > without including <linux/acpi.h>, thus without _LINUX defined.  As there is
> > no issues encountered when we compile ACPICA code without _LINUX defined,
> > it is OK to remove _LINUX from <linux/acpi.h> now.
> >
> > Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
> > ---
> >  include/linux/acpi.h |    4 ----
> >  1 file changed, 4 deletions(-)
> >
> > diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> > index 7a8f2cd..9c559f7 100644
> > --- a/include/linux/acpi.h
> > +++ b/include/linux/acpi.h
> > @@ -31,10 +31,6 @@
> >
> >  #ifdef	CONFIG_ACPI
> >
> > -#ifndef _LINUX
> > -#define _LINUX
> > -#endif
> > -
> >  #include <linux/list.h>
> >  #include <linux/mod_devicetable.h>
> 
> What about <acpi/platform/acenv.h>?  Should it still check if _LINUX is defined
> after this change?

If you mean these lines:
  #if defined(_LINUX) || defined(__linux__)
  #include <acpi/platform/aclinux.h>
After deleting "_LINUX" from <linux/acpi.h>, acenv.h still can include aclinux.h because of "__linux__".
Actually all drivers/acpi/acpica source files are compiled without including <linux/acpi.h>, so "_LINUX" defined in this file is useless to Linux.
We needn't delete "_LINUX" from acenv.h.

"_LINUX" is only used in ACPICA makefiles, Linux never uses it:
  https://github.com/acpica/acpica/blob/master/generate/unix/Makefile.config
ACPICA can be compiled using the following make command:
  make HOST=_LINUX
I think this is the only usage of "_LINUX" for now.

Thanks and best regards
-Lv

> 
> 
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
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