[src/trunk]: src/sys/sys Add a comment to explain the purpose of POWER_IOC_GE...

[kre <kre%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e49df37a6580
branches:  trunk
changeset: 363564:e49df37a6580
user:      kre <kre%NetBSD.org@localhost>
date:      Wed Aug 01 20:09:34 2018 +0000

description:
Add a comment to explain the purpose of POWER_IOC_GET_TYPE_WITH_LOSSAGE
and also define it only for the kernel, userland should never see that.

diffstat:

 sys/sys/power.h |  9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diffs (23 lines):

diff -r 3f07ae4f9ce4 -r e49df37a6580 sys/sys/power.h
--- a/sys/sys/power.h   Wed Aug 01 20:04:09 2018 +0000
+++ b/sys/sys/power.h   Wed Aug 01 20:09:34 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: power.h,v 1.20 2015/01/06 15:39:54 bouyer Exp $        */
+/*     $NetBSD: power.h,v 1.21 2018/08/01 20:09:34 kre Exp $   */
 
 /*
  * Copyright (c) 2003 Wasabi Systems, Inc.
@@ -282,6 +282,13 @@
        char    power_type[32];
 };
 #define        POWER_IOC_GET_TYPE      _IOR('P', 0, struct power_type)
+
+#ifdef _KERNEL
+/*
+ * so the kernel can provide binary compat for applications
+ * built when POWER_IOC_GET_TYPE was incorrectly defined as:
+ */
 #define        POWER_IOC_GET_TYPE_WITH_LOSSAGE _IOR('P', 0, sizeof(struct power_type))
+#endif
 
 #endif /* _SYS_POWER_H_ */