[src/trunk]: src/share/man/man4 Add description about channel limitation intr...

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

details:   https://anonhg.NetBSD.org/src/rev/51a1591f4fad
branches:  trunk
changeset: 1008598:51a1591f4fad
user:      isaki <isaki%NetBSD.org@localhost>
date:      Sat Mar 28 04:55:08 2020 +0000

description:
Add description about channel limitation introduced in audio.c 1.43.
PR kern/54973.

diffstat:

 share/man/man4/audio.4 |  19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diffs (40 lines):

diff -r be079f2379b8 -r 51a1591f4fad share/man/man4/audio.4
--- a/share/man/man4/audio.4    Sat Mar 28 04:21:58 2020 +0000
+++ b/share/man/man4/audio.4    Sat Mar 28 04:55:08 2020 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: audio.4,v 1.101 2020/03/28 04:21:58 isaki Exp $
+.\"    $NetBSD: audio.4,v 1.102 2020/03/28 04:55:08 isaki Exp $
 .\"
 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -400,18 +400,25 @@
 Dolby Digital AC3
 .El
 .Pp
-Regardless of formats supported by underlying driver, the
+The
 .Nm
 driver accepts the following formats.
 .Va encoding
 and
 .Va precision
 are one of the values obtained by
-.Dv AUDIO_GETENC .
+.Dv AUDIO_GETENC ,
+regardless of formats supported by underlying driver.
+.Va frequency
+ranges from 1000Hz to 192000Hz,
+regardless of frequency (ranges) supported by underlying driver.
 .Va channels
-ranges from 1 to 12.
-.Va frequency
-ranges from 1000Hz to 192000Hz.
+depends your underlying driver.
+If the underlying driver only supports monaural (1channel)
+or stereo (2channels), you can specify 1 or 2 regardless of
+number of channels supported by underlying driver.
+If the underlying driver supports three or more channels, you can specify
+the number of channels supported by the underlying driver or less. 
 .Pp
 The
 .Va gain ,