[src/trunk]: src/sys/dev Increment sc_opens only after channel is set up.

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

details:   https://anonhg.NetBSD.org/src/rev/d3c5c5e23297
branches:  trunk
changeset: 350618:d3c5c5e23297
user:      nat <nat%NetBSD.org@localhost>
date:      Sat Jan 14 20:05:37 2017 +0000

description:
Increment sc_opens only after channel is set up.

It should help PR kern/51746: Panics from audio.

diffstat:

 sys/dev/audio.c |  25 ++++++++++---------------
 1 files changed, 10 insertions(+), 15 deletions(-)

diffs (90 lines):

diff -r 4012f0ad3ac0 -r d3c5c5e23297 sys/dev/audio.c
--- a/sys/dev/audio.c   Sat Jan 14 19:32:10 2017 +0000
+++ b/sys/dev/audio.c   Sat Jan 14 20:05:37 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: audio.c,v 1.289 2017/01/02 00:16:45 nat Exp $  */
+/*     $NetBSD: audio.c,v 1.290 2017/01/14 20:05:37 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 1.289 2017/01/02 00:16:45 nat Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.290 2017/01/14 20:05:37 nat Exp $");
 
 #include "audio.h"
 #if NAUDIO > 0
@@ -1783,7 +1783,7 @@
            (sc->sc_vchan[n]->sc_open & AUOPEN_READ)) {
                audio_init_ringbuffer(sc, &sc->sc_vchan[n]->sc_mrr,
                    AUMODE_RECORD);
-               if (sc->sc_opens == 1 && hw->init_input &&
+               if (sc->sc_opens == 0 && hw->init_input &&
                    (sc->sc_vchan[n]->sc_mode & AUMODE_RECORD)) {
                        error = hw->init_input(sc->hw_hdl, vc->sc_mrr.s.start,
                                       vc->sc_mrr.s.end - vc->sc_mrr.s.start);
@@ -1797,7 +1797,7 @@
                audio_init_ringbuffer(sc, &sc->sc_vchan[n]->sc_mpr,
                    AUMODE_PLAY);
                sc->sc_vchan[n]->sc_sil_count = 0;
-               if (sc->sc_opens == 1 && hw->init_output &&
+               if (sc->sc_opens == 0 && hw->init_output &&
                    (sc->sc_vchan[n]->sc_mode & AUMODE_PLAY)) {
                        error = hw->init_output(sc->hw_hdl, vc->sc_mpr.s.start,
                                        vc->sc_mpr.s.end - vc->sc_mpr.s.start);
@@ -1921,9 +1921,6 @@
                return EBUSY;
        }
 
-       sc->sc_opens++;
-       sc->sc_audiopid[n].pid = curproc->p_pid;
-       sc->sc_despid[n].pid = curproc->p_pid;
        error = audio_alloc_ring(sc, &vc->sc_mpr,
                    AUMODE_PLAY, AU_RING_SIZE);
        if (!error) {
@@ -1931,22 +1928,16 @@
                    AUMODE_RECORD, AU_RING_SIZE);
        }
        if (error) {
-               sc->sc_opens--;
-               sc->sc_audiopid[n].pid = -1;
-               sc->sc_despid[n].pid = -1;
                kmem_free(vc, sizeof(struct virtual_channel));
                return error;
        }
 
-       if (sc->sc_opens == 1) {
+       if (sc->sc_opens == 0) {
                if (hw->open != NULL) {
                        mutex_enter(sc->sc_intr_lock);
                        error = hw->open(sc->hw_hdl, flags);
                        mutex_exit(sc->sc_intr_lock);
                        if (error) {
-                               sc->sc_opens--;
-                               sc->sc_audiopid[n].pid = -1;
-                               sc->sc_despid[n].pid = -1;
                                kmem_free(vc,
                                    sizeof(struct virtual_channel));
                                return error;
@@ -1972,7 +1963,6 @@
        if (flags & FREAD) {
                vc->sc_open |= AUOPEN_READ;
                mode |= AUMODE_RECORD;
-               sc->sc_recopens++;
        }
        if (flags & FWRITE) {
                vc->sc_open |= AUOPEN_WRITE;
@@ -2012,6 +2002,11 @@
        DPRINTF(("audio_open: done sc_mode = 0x%x\n", vc->sc_mode));
 
        mutex_enter(sc->sc_intr_lock);
+       if (flags & FREAD)
+               sc->sc_recopens++;
+       sc->sc_opens++;
+       sc->sc_audiopid[n].pid = curproc->p_pid;
+       sc->sc_despid[n].pid = curproc->p_pid;
        sc->sc_nmixer_states += 2;
        mutex_exit(sc->sc_intr_lock);