Hi, > From: Wysocki, Rafael J > Sent: Tuesday, April 29, 2014 4:27 AM > > On 4/28/2014 6:10 AM, Zheng, Lv wrote: > > 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. > > Well, my point was: If we delete the definition of _LINUX, why don't we > drop the symbol itself from everywhere along with it? > > It definitely is not useful to refer to a symbol that's never defined, > is it? It sounds like I should clean up acenv.h first than deleting this. OK, I'll drop this patch from this series. I might re-do the deletion after cleaning up the acenv.h. Thanks and best regards -Lv > > Rafael ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f