[src/trunk]: src/sys/kern Schedule wakeups asynchronously in rnd_extract_data.

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

details:   https://anonhg.NetBSD.org/src/rev/f138d4fc9056
branches:  trunk
changeset: 789619:f138d4fc9056
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Tue Aug 27 14:01:35 2013 +0000

description:
Schedule wakeups asynchronously in rnd_extract_data.

Otherwise, rndsink_request takes rndsinks_lock and calls
rnd_extract_data, which synchronously calls rndsinks_distribute,
which takes rndsinks_lock -> boom.

This is a stop-gap on a stop-gap on a stop-gap; we really ought to
back out all of these stop-gaps, make bcm2835_rng call rnd_add_data
asynchronously to work around the original symptom, and design a real
solution when we have time to sort this mess out properly.

diffstat:

 sys/kern/kern_rndq.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (27 lines):

diff -r d80efe8ee684 -r f138d4fc9056 sys/kern/kern_rndq.c
--- a/sys/kern/kern_rndq.c      Tue Aug 27 13:12:29 2013 +0000
+++ b/sys/kern/kern_rndq.c      Tue Aug 27 14:01:35 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_rndq.c,v 1.16 2013/08/26 23:41:24 tls Exp $       */
+/*     $NetBSD: kern_rndq.c,v 1.17 2013/08/27 14:01:35 riastradh Exp $ */
 
 /*-
  * Copyright (c) 1997-2013 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.16 2013/08/26 23:41:24 tls Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.17 2013/08/27 14:01:35 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/ioctl.h>
@@ -1038,7 +1038,7 @@
        mutex_spin_exit(&rndpool_mtx);
 
        if (wake) {
-               rnd_wakeup_readers();
+               rnd_schedule_wakeup();
        }
 
        return retval;