From c8e35e01511e6239dbb4d3b044788e2c7c412b85 Mon Sep 17 00:00:00 2001
From: isaki <isaki@NetBSD.org>
Date: Fri, 29 May 2020 03:09:14 +0000
Subject: [PATCH] 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.

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

diff --git a/sys/dev/audio/audio.c b/sys/dev/audio/audio.c
index fad1086473a3..829af40cccff 100644
--- a/sys/dev/audio/audio.c
+++ b/sys/dev/audio/audio.c
@@ -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 @@ audio_track_waitio(struct audio_softc *sc, audio_track_t *track)
 	/* 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 @@ audio_suspend(device_t dv, const pmf_qual_t *qual)
 	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 @@ audio_resume(device_t dv, const pmf_qual_t *qual)
 	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 --git a/sys/dev/audio/audiovar.h b/sys/dev/audio/audiovar.h
index ea0cbb442cbd..c9ddc7d34b28 100644
--- a/sys/dev/audio/audiovar.h
+++ b/sys/dev/audio/audiovar.h
@@ -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.
@@ -234,6 +234,12 @@ struct audio_softc {
 	 */
 	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.