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[src/trunk]: src/sys/dev/audio Set AUDIO_BLK_MS 40 msec on other old(slow) ar...
details: https://anonhg.NetBSD.org/src/rev/5b41cbb6fceb
branches: trunk
changeset: 971594:5b41cbb6fceb
user: isaki <isaki%NetBSD.org@localhost>
date: Wed Apr 29 03:58:27 2020 +0000
description:
Set AUDIO_BLK_MS 40 msec on other old(slow) architectures not only m68k.
Thanks tsutsui@ for comment about architecture choice.
And move it from audiodef.h to audio.c as suggested by joerg@.
diffstat:
sys/dev/audio/audio.c | 39 +++++++++++++++++++++++++++++++++++++--
sys/dev/audio/audiodef.h | 21 +--------------------
2 files changed, 38 insertions(+), 22 deletions(-)
diffs (95 lines):
diff -r 75622a6ddedc -r 5b41cbb6fceb sys/dev/audio/audio.c
--- a/sys/dev/audio/audio.c Wed Apr 29 02:16:56 2020 +0000
+++ b/sys/dev/audio/audio.c Wed Apr 29 03:58:27 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: audio.c,v 1.67 2020/04/19 03:52:22 isaki Exp $ */
+/* $NetBSD: audio.c,v 1.68 2020/04/29 03:58:27 isaki Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -138,7 +138,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.67 2020/04/19 03:52:22 isaki Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.68 2020/04/29 03:58:27 isaki Exp $");
#ifdef _KERNEL_OPT
#include "audio.h"
@@ -451,6 +451,41 @@
#define SPECIFIED(x) ((x) != ~0)
#define SPECIFIED_CH(x) ((x) != (u_char)~0)
+/*
+ * Default hardware blocksize in msec.
+ *
+ * We use 10 msec for most platforms. This period is good enough to play
+ * audio and video synchronizely.
+ * In contrast, for very old platforms, this is usually too short and too
+ * severe. Also such platforms usually can not play video confortably, so
+ * it's not so important to make the blocksize shorter.
+ * In either case, you can overwrite AUDIO_BLK_MS by your kernel
+ * configuration file if you wish.
+ *
+ * 40 msec was initially choosen for the following reason:
+ * (1 / 40ms) = 25 = 5^2. Thus, the frequency is factored by 5.
+ * In this case, the number of frames in a block can be an integer
+ * even if the frequency is a multiple of 100 (44100, 48000, etc),
+ * or even if 15625Hz (vs(4)).
+ */
+#if defined(__hppa__) || \
+ defined(__m68k__) || \
+ defined(__sh3__) || \
+ (defined(__sparc__) && !defined(__sparc64__)) || \
+ defined(__vax__)
+#define AUDIO_TOO_SLOW_ARCHS 1
+#endif
+
+#if !defined(AUDIO_BLK_MS)
+# if defined(AUDIO_TOO_SLOW_ARCHS)
+# define AUDIO_BLK_MS 40
+# else
+# define AUDIO_BLK_MS 10
+# endif
+#endif
+
+#undef AUDIO_TOO_SLOW_ARCHS
+
/* Device timeout in msec */
#define AUDIO_TIMEOUT (3000)
diff -r 75622a6ddedc -r 5b41cbb6fceb sys/dev/audio/audiodef.h
--- a/sys/dev/audio/audiodef.h Wed Apr 29 02:16:56 2020 +0000
+++ b/sys/dev/audio/audiodef.h Wed Apr 29 03:58:27 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: audiodef.h,v 1.13 2020/03/28 08:35:36 isaki Exp $ */
+/* $NetBSD: audiodef.h,v 1.14 2020/04/29 03:58:27 isaki Exp $ */
/*
* Copyright (C) 2017 Tetsuya Isaki. All rights reserved.
@@ -43,25 +43,6 @@
#define AUMINNOBLK (3)
/*
- * Hardware blocksize in msec.
- * We use 10 msec as default for most platforms. But it's too severe for
- * most m68k.
- *
- * 40 msec was initially choosen for the following reason:
- * (1 / 40ms) = 25 = 5^2. Thus, the frequency is factored by 5.
- * In this case, the number of frames in a block can be an integer
- * even if the frequency is a multiple of 100 (44100, 48000, etc),
- * or even if 15625Hz (vs(4)).
- */
-#if !defined(AUDIO_BLK_MS)
-# if defined(__m68k__)
-# define AUDIO_BLK_MS 40
-# else
-# define AUDIO_BLK_MS 10
-# endif
-#endif
-
-/*
* Whether the playback mixer use single buffer mode.
* It reduces the latency one block but needs machine power.
* In case of the double buffer (as default), it increases the latency
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