[src/trunk]: src/sys/dev Rework of play/rec threads to ensure effective use o...

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

details:   https://anonhg.NetBSD.org/src/rev/195a333ac62b
branches:  trunk
changeset: 358582:195a333ac62b
user:      nat <nat%NetBSD.org@localhost>
date:      Tue Jan 09 04:10:27 2018 +0000

description:
Rework of play/rec threads to ensure effective use of locks.

Addresses part of PR kern/52889 where the mixing thread would not exit on
audio detach.

diffstat:

 sys/dev/audio.c |  46 ++++++++++++++++++++++++++--------------------
 1 files changed, 26 insertions(+), 20 deletions(-)

diffs (83 lines):

diff -r bd01d89b445b -r 195a333ac62b sys/dev/audio.c
--- a/sys/dev/audio.c   Tue Jan 09 03:31:12 2018 +0000
+++ b/sys/dev/audio.c   Tue Jan 09 04:10:27 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: audio.c,v 1.447 2018/01/06 23:15:36 nat Exp $  */
+/*     $NetBSD: audio.c,v 1.448 2018/01/09 04:10:27 nat Exp $  */
 
 /*-
  * Copyright (c) 2016 Nathanial Sloss <nathanialsloss%yahoo.com.au@localhost>
@@ -148,7 +148,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.447 2018/01/06 23:15:36 nat Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.448 2018/01/09 04:10:27 nat Exp $");
 
 #ifdef _KERNEL_OPT
 #include "audio.h"
@@ -5858,22 +5858,24 @@
        sc = (struct audio_softc *)v;
 
        for (;;) {
-               mutex_enter(sc->sc_intr_lock);
-               cv_wait_sig(&sc->sc_condvar, sc->sc_intr_lock);
+               mutex_enter(sc->sc_lock);
                if (sc->sc_dying) {
-                       mutex_exit(sc->sc_intr_lock);
+                       mutex_exit(sc->sc_lock);
                        kthread_exit(0);
                }
-
-               while (sc->sc_usemixer &&
+               if (!sc->sc_trigger_started)
+                       goto play_wait;
+
+               while (!sc->sc_dying && sc->sc_usemixer &&
                    audio_stream_get_used(&sc->sc_mixring.sc_mpr.s) <
-                                               sc->sc_mixring.sc_mpr.blksize) {
-                       mutex_exit(sc->sc_intr_lock);
-                       mutex_enter(sc->sc_lock);
+                                               sc->sc_mixring.sc_mpr.blksize)
                        audio_mix(sc);
-                       mutex_exit(sc->sc_lock);
-                       mutex_enter(sc->sc_intr_lock);
-               }
+
+play_wait:
+               mutex_exit(sc->sc_lock);
+
+               mutex_enter(sc->sc_intr_lock);
+               cv_wait_sig(&sc->sc_condvar, sc->sc_intr_lock);
                mutex_exit(sc->sc_intr_lock);
        }
 }
@@ -5886,17 +5888,21 @@
        sc = (struct audio_softc *)v;
 
        for (;;) {
-               mutex_enter(sc->sc_intr_lock);
-               cv_wait_sig(&sc->sc_rcondvar, sc->sc_intr_lock);
+               mutex_enter(sc->sc_lock);
                if (sc->sc_dying) {
-                       mutex_exit(sc->sc_intr_lock);
+                       mutex_exit(sc->sc_lock);
                        kthread_exit(0);
                }
+               if (!sc->sc_rec_started)
+                       goto rec_wait;
+
+               audio_upmix(sc);
+rec_wait:
+               mutex_exit(sc->sc_lock);
+
+               mutex_enter(sc->sc_intr_lock);
+               cv_wait_sig(&sc->sc_rcondvar, sc->sc_intr_lock);
                mutex_exit(sc->sc_intr_lock);
-
-               mutex_enter(sc->sc_lock);
-               audio_upmix(sc);
-               mutex_exit(sc->sc_lock);
        }
 
 }