[src/trunk]: src/sys/dev Fix channel assignment for multiple channels.

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

details:   https://anonhg.NetBSD.org/src/rev/7198e9200087
branches:  trunk
changeset: 822629:7198e9200087
user:      nat <nat%NetBSD.org@localhost>
date:      Wed Mar 29 06:24:22 2017 +0000

description:
Fix channel assignment for multiple channels.

This fixes a problem if two or more channels are opened and the first
(any but last channel) is closed and new channels are opened.

diffstat:

 sys/dev/audio.c |  15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diffs (36 lines):

diff -r 26ffe28e2270 -r 7198e9200087 sys/dev/audio.c
--- a/sys/dev/audio.c   Tue Mar 28 20:32:43 2017 +0000
+++ b/sys/dev/audio.c   Wed Mar 29 06:24:22 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: audio.c,v 1.318 2017/03/27 23:25:24 nat Exp $  */
+/*     $NetBSD: audio.c,v 1.319 2017/03/29 06:24:22 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 1.318 2017/03/27 23:25:24 nat Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.319 2017/03/29 06:24:22 nat Exp $");
 
 #include "audio.h"
 #if NAUDIO > 0
@@ -2084,9 +2084,14 @@
        hw = sc->hw_if;
        if (hw == NULL)
                return ENXIO;
-       n = 0;
-       SIMPLEQ_FOREACH(chan, &sc->sc_audiochan, entries)
-               n++;
+       n = 1;
+       SIMPLEQ_FOREACH(chan, &sc->sc_audiochan, entries) {
+               if (chan == SIMPLEQ_FIRST(&sc->sc_audiochan))
+                       continue;
+               n = chan->chan + 1;
+       }
+       if (n < 0)
+               return ENOMEM;
 
        chan = kmem_zalloc(sizeof(struct audio_chan), KM_SLEEP);
        vc = kmem_zalloc(sizeof(struct virtual_channel), KM_SLEEP);