Re: CVS commit: src/sys

[Tetsuya Isaki <isaki%pastel-flower.jp@localhost>]

At Wed, 29 Apr 2020 21:59:59 +0000,
Andrew Doran wrote:
> > > How about this diff?
> > > The old platforms are the same as before, hppa, m68k, sh3, sparc(!64)
> > > and vax.
> > 
> > machine/param.h seems more natural to me.  I don't have a strong opinion
> > though.
> 
> .. I mean, if it's a "tuneable" value like this rather than a constant like
> __HAVE_SLOW_COMPUTER. :-)

I see.  I like this feeling. (not strong opinion too though)
How about you, mrg@?

Thanks,
---
Tetsuya Isaki <isaki%pastel-flower.jp@localhost / isaki%NetBSD.org@localhost>

diff --git a/sys/arch/hppa/include/param.h b/sys/arch/hppa/include/param.h
index 39ce45623..69686c405 100644
--- a/sys/arch/hppa/include/param.h
+++ b/sys/arch/hppa/include/param.h
@@ -88,3 +88,8 @@
 
 #define btop(x)		((unsigned long)(x) >> PGSHIFT)
 #define ptob(x)		((unsigned long)(x) << PGSHIFT)
+
+/* Default audio blocksize in msec.  See sys/dev/audio/audio.c */
+#if defined(_KERNEL)
+#define	__AUDIO_BLK_MS (40)
+#endif
diff --git a/sys/arch/m68k/include/param.h b/sys/arch/m68k/include/param.h
index f0bbe169e..ae67a324c 100644
--- a/sys/arch/m68k/include/param.h
+++ b/sys/arch/m68k/include/param.h
@@ -95,4 +95,9 @@
 #define	m68k_btop(x)		((vaddr_t)(x) >> PGSHIFT)
 #define	m68k_ptob(x)		((vaddr_t)(x) << PGSHIFT)
 
+/* Default audio blocksize in msec.  See sys/dev/audio/audio.c */
+#if defined(_KERNEL)
+#define	__AUDIO_BLK_MS (40)
+#endif
+
 #endif	/* !_M68K_PARAM_H_ */
diff --git a/sys/arch/sh3/include/param.h b/sys/arch/sh3/include/param.h
index 547b791f2..66b6d578e 100644
--- a/sys/arch/sh3/include/param.h
+++ b/sys/arch/sh3/include/param.h
@@ -91,4 +91,9 @@
 #define	NKMEMPAGES_MIN_DEFAULT	((16 * 1024 * 1024) >> PAGE_SHIFT)
 #define	NKMEMPAGES_MAX_DEFAULT	((128 * 1024 * 1024) >> PAGE_SHIFT)
 
+/* Default audio blocksize in msec.  See sys/dev/audio/audio.c */
+#if defined(_KERNEL)
+#define	__AUDIO_BLK_MS (40)
+#endif
+
 #endif /* !_SH3_PARAM_H_ */
diff --git a/sys/arch/sparc/include/param.h b/sys/arch/sparc/include/param.h
index f6112f886..2225a52a2 100644
--- a/sys/arch/sparc/include/param.h
+++ b/sys/arch/sparc/include/param.h
@@ -155,4 +155,7 @@ extern void	delay(unsigned int);
 #	define PGSHIFT		pgshift
 #endif
 
+/* Default audio blocksize in msec.  See sys/dev/audio/audio.c */
+#define	__AUDIO_BLK_MS (40)
+
 #endif /* _KERNEL || _STANDALONE */
diff --git a/sys/arch/vax/include/param.h b/sys/arch/vax/include/param.h
index 57685709c..f350237b7 100644
--- a/sys/arch/vax/include/param.h
+++ b/sys/arch/vax/include/param.h
@@ -118,6 +118,10 @@ void	delay(int);
 
 #define	DELAY(x) delay(x)
 #define	MAXEXEC	1
+
+/* Default audio blocksize in msec.  See sys/dev/audio/audio.c */
+#define	__AUDIO_BLK_MS (40)
+
 #endif /* _KERNEL */
 
 #endif /* _VAX_PARAM_H_ */
diff --git a/sys/dev/audio/audio.c b/sys/dev/audio/audio.c
index 13386ccfb..ef1424d48 100644
--- a/sys/dev/audio/audio.c
+++ b/sys/dev/audio/audio.c
@@ -454,38 +454,25 @@ audio_track_bufstat(audio_track_t *track, struct audio_track_debugbuf *buf)
 /*
  * Default hardware blocksize in msec.
  *
- * We use 10 msec for most platforms.  This period is good enough to play
- * audio and video synchronizely.
+ * We use 10 msec for most modern 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.
+ * it's not so important to make the blocksize shorter.  If the platform
+ * defines its own value as __AUDIO_BLK_MS in its <machine/param.h>, it
+ * uses this instead.
+ *
  * 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
+# if defined(__AUDIO_BLK_MS)
+#  define AUDIO_BLK_MS __AUDIO_BLK_MS
 # else
-#  define AUDIO_BLK_MS 10
+#  define AUDIO_BLK_MS (10)
 # endif
 #endif
 
-#undef AUDIO_TOO_SLOW_ARCHS
-
 /* Device timeout in msec */
 #define AUDIO_TIMEOUT	(3000)