[src/trunk]: src/sys/dev/audio Fix suspend/resume.

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

details:   https://anonhg.NetBSD.org/src/rev/00dad77c824f
branches:  trunk
changeset: 933714:00dad77c824f
user:      isaki <isaki%NetBSD.org@localhost>
date:      Fri May 29 03:09:14 2020 +0000

description:
Fix suspend/resume.
- Revert temporary usage of sc_[pr]busy during suspend.  These indicate
  whether the mixer needs to be restarted or not.
- Avoid timeout error when about to suspend.

diffstat:

 sys/dev/audio/audio.c    |  33 +++++++++++++++++++++++++++++----
 sys/dev/audio/audiovar.h |   8 +++++++-
 2 files changed, 36 insertions(+), 5 deletions(-)

diffs (104 lines):

diff -r 23d8bff1cb82 -r 00dad77c824f sys/dev/audio/audio.c
--- a/sys/dev/audio/audio.c     Fri May 29 01:20:43 2020 +0000
+++ b/sys/dev/audio/audio.c     Fri May 29 03:09:14 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: audio.c,v 1.74 2020/05/26 15:20:16 nia Exp $   */
+/*     $NetBSD: audio.c,v 1.75 2020/05/29 03:09:14 isaki Exp $ */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -138,7 +138,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.74 2020/05/26 15:20:16 nia Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.75 2020/05/29 03:09:14 isaki Exp $");
 
 #ifdef _KERNEL_OPT
 #include "audio.h"
@@ -1566,6 +1566,13 @@
        /* Wait for pending I/O to complete. */
        error = cv_timedwait_sig(&track->mixer->outcv, sc->sc_lock,
            mstohz(AUDIO_TIMEOUT));
+       if (sc->sc_suspending) {
+               /* If it's about to suspend, ignore timeout error. */
+               if (error == EWOULDBLOCK) {
+                       TRACET(2, track, "timeout (suspending)");
+                       return 0;
+               }
+       }
        if (sc->sc_dying) {
                error = EIO;
        }
@@ -7754,13 +7761,18 @@
        error = audio_exlock_mutex_enter(sc);
        if (error)
                return error;
+       sc->sc_suspending = true;
        audio_mixer_capture(sc);
 
        if (sc->sc_pbusy) {
                audio_pmixer_halt(sc);
+               /* Reuse this as need-to-restart flag while suspending */
+               sc->sc_pbusy = true;
        }
        if (sc->sc_rbusy) {
                audio_rmixer_halt(sc);
+               /* Reuse this as need-to-restart flag while suspending */
+               sc->sc_rbusy = true;
        }
 
 #ifdef AUDIO_PM_IDLE
@@ -7782,15 +7794,28 @@
        if (error)
                return error;
 
+       sc->sc_suspending = false;
        audio_mixer_restore(sc);
        /* XXX ? */
        AUDIO_INITINFO(&ai);
        audio_hw_setinfo(sc, &ai, NULL);
 
-       if (!sc->sc_pbusy)
+       /*
+        * During from suspend to resume here, sc_[pr]busy is used as
+        * need-to-restart flag temporarily.  After this point,
+        * sc_[pr]busy is returned to its original usage (busy flag).
+        * And note that sc_[pr]busy must be false to call [pr]mixer_start().
+        */
+       if (sc->sc_pbusy) {
+               /* pmixer_start() requires pbusy is false */
+               sc->sc_pbusy = false;
                audio_pmixer_start(sc, true);
-       if (!sc->sc_rbusy && sc->sc_ropens > 0)
+       }
+       if (sc->sc_rbusy) {
+               /* rmixer_start() requires rbusy is false */
+               sc->sc_rbusy = false;
                audio_rmixer_start(sc);
+       }
 
        audio_exlock_mutex_exit(sc);
 
diff -r 23d8bff1cb82 -r 00dad77c824f sys/dev/audio/audiovar.h
--- a/sys/dev/audio/audiovar.h  Fri May 29 01:20:43 2020 +0000
+++ b/sys/dev/audio/audiovar.h  Fri May 29 03:09:14 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: audiovar.h,v 1.11 2020/03/07 06:25:57 isaki Exp $      */
+/*     $NetBSD: audiovar.h,v 1.12 2020/05/29 03:09:14 isaki Exp $      */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -235,6 +235,12 @@
        bool            sc_dying;
 
        /*
+        * Indicates that about to suspend.
+        * Must be protected by sc_lock.
+        */
+       bool            sc_suspending;
+
+       /*
         * If multiuser is false, other users who have different euid
         * than the first user cannot open this device.
         * Must be protected by sc_exlock.