[src/trunk]: src/sys/arch/sparc64/sparc64 sun4v: Improve comment for next_sti...

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

details:   https://anonhg.NetBSD.org/src/rev/da7a339046f1
branches:  trunk
changeset: 448765:da7a339046f1
user:      palle <palle%NetBSD.org@localhost>
date:      Fri Feb 08 20:34:23 2019 +0000

description:
sun4v: Improve comment for next_stick_init() - no functional changes

diffstat:

 sys/arch/sparc64/sparc64/locore.s |  5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diffs (19 lines):

diff -r 2fcaa080d658 -r da7a339046f1 sys/arch/sparc64/sparc64/locore.s
--- a/sys/arch/sparc64/sparc64/locore.s Fri Feb 08 20:29:05 2019 +0000
+++ b/sys/arch/sparc64/sparc64/locore.s Fri Feb 08 20:34:23 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: locore.s,v 1.418 2019/02/08 20:14:51 palle Exp $       */
+/*     $NetBSD: locore.s,v 1.419 2019/02/08 20:34:23 palle Exp $       */
 
 /*
  * Copyright (c) 2006-2010 Matthew R. Green
@@ -7513,6 +7513,9 @@
  * Sets the %stick_cmpr register to the value retrieved from %stick so
  * next_stick() does not spend too much time in the function when called
  * for the first time.
+ * This has been observed on (at least) a SPARC-T5 (sun4v) system where
+ * the %stick_cmpr ends up being less than the %stick value and then
+ * the stickitr() interrupt is never triggered.
  */
 ENTRY(next_stick_init)
        rd      STICK, %o0