[src/riastradh-drm2]: src/sys/external/bsd/drm2/drm Add comment explaining wh...

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

details:   https://anonhg.NetBSD.org/src/rev/9a8796be8729
branches:  riastradh-drm2
changeset: 788191:9a8796be8729
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Jul 24 02:38:23 2013 +0000

description:
Add comment explaining why drm_idlelock_* are not yet implemented.

diffstat:

 sys/external/bsd/drm2/drm/drm_lock.c |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (30 lines):

diff -r 95e58ac16662 -r 9a8796be8729 sys/external/bsd/drm2/drm/drm_lock.c
--- a/sys/external/bsd/drm2/drm/drm_lock.c      Wed Jul 24 02:38:06 2013 +0000
+++ b/sys/external/bsd/drm2/drm/drm_lock.c      Wed Jul 24 02:38:23 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: drm_lock.c,v 1.1.2.2 2013/07/24 02:35:35 riastradh Exp $       */
+/*     $NetBSD: drm_lock.c,v 1.1.2.3 2013/07/24 02:38:23 riastradh Exp $       */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -43,7 +43,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: drm_lock.c,v 1.1.2.2 2013/07/24 02:35:35 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: drm_lock.c,v 1.1.2.3 2013/07/24 02:38:23 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/errno.h>
@@ -209,6 +209,11 @@
 
 /*
  * Take the lock for the kernel's use.
+ *
+ * XXX This is unimplemented because it's not clear that the Linux code
+ * makes sense at all.  Linux's drm_idlelock_take never blocks, but it
+ * doesn't guarantee that the kernel holds the lock on return!  For
+ * now, I'll hope that the code paths relying on this don't matter yet.
  */
 void
 drm_idlelock_take(struct drm_lock_data *lock_data __unused)