[src/trunk]: src/sys/dev/isa avoid mutex locking botch and introduce an unloc...

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

details:   https://anonhg.NetBSD.org/src/rev/4e2a837ada3d
branches:  trunk
changeset: 765318:4e2a837ada3d
user:      mrg <mrg%NetBSD.org@localhost>
date:      Tue May 24 09:28:03 2011 +0000

description:
avoid mutex locking botch and introduce an unlocked version of
pcppi_bell_stop().  fixes a problem reported in private email.

diffstat:

 sys/dev/isa/pcppi.c |  21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

diffs (73 lines):

diff -r b973fafb7ef6 -r 4e2a837ada3d sys/dev/isa/pcppi.c
--- a/sys/dev/isa/pcppi.c       Tue May 24 08:54:40 2011 +0000
+++ b/sys/dev/isa/pcppi.c       Tue May 24 09:28:03 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pcppi.c,v 1.36 2011/05/03 04:27:13 mrg Exp $ */
+/* $NetBSD: pcppi.c,v 1.37 2011/05/24 09:28:03 mrg Exp $ */
 
 /*
  * Copyright (c) 1996 Carnegie-Mellon University.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pcppi.c,v 1.36 2011/05/03 04:27:13 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pcppi.c,v 1.37 2011/05/24 09:28:03 mrg Exp $");
 
 #include "attimer.h"
 
@@ -66,6 +66,7 @@
     DVF_DETACH_SHUTDOWN);
 
 static int pcppisearch(device_t, cfdata_t, const int *, void *);
+static void pcppi_bell_stop_unlocked(void*);
 static void pcppi_bell_stop(void*);
 
 #if NATTIMER > 0
@@ -285,7 +286,7 @@
                        cv_broadcast(&sc->sc_stop_cv);
        }
        if (pitch == 0 || period == 0) {
-               pcppi_bell_stop(sc);
+               pcppi_bell_stop_unlocked(sc);
                sc->sc_bellpitch = 0;
                mutex_exit(&sc->sc_lock);
                return;
@@ -305,7 +306,7 @@
        sc->sc_bellactive = 1;
        if (slp & PCPPI_BELL_POLL) {
                delay((period * 1000000) / hz);
-               pcppi_bell_stop(sc);
+               pcppi_bell_stop_unlocked(sc);
        } else {
                sc->sc_timeout = 1;
                callout_reset(&sc->sc_bell_ch, period, pcppi_bell_stop, sc);
@@ -319,11 +320,10 @@
 }
 
 static void
-pcppi_bell_stop(void *arg)
+pcppi_bell_stop_unlocked(void *arg)
 {
        struct pcppi_softc *sc = arg;
 
-       mutex_enter(&sc->sc_lock);
        sc->sc_timeout = 0;
 
        /* disable bell */
@@ -333,6 +333,15 @@
        sc->sc_bellactive = 0;
        if (sc->sc_slp)
                cv_broadcast(&sc->sc_stop_cv);
+}
+
+static void
+pcppi_bell_stop(void *arg)
+{
+       struct pcppi_softc *sc = arg;
+
+       mutex_enter(&sc->sc_lock);
+       pcppi_bell_stop_unlocked(arg);
        mutex_exit(&sc->sc_lock);
 }