[src/trunk]: src/share/man/man4 Revert 1.96, 1.97 and 1.100. (no response fr...

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

details:   https://anonhg.NetBSD.org/src/rev/be079f2379b8
branches:  trunk
changeset: 1008597:be079f2379b8
user:      isaki <isaki%NetBSD.org@localhost>
date:      Sat Mar 28 04:21:58 2020 +0000

description:
Revert 1.96, 1.97 and 1.100.  (no response from nia@)
These changes are not correct nor notable unresolvable problem.
If you find any problems, please send a report before changing manpage.

diffstat:

 share/man/man4/audio.4 |  20 +++++++++++---------
 1 files changed, 11 insertions(+), 9 deletions(-)

diffs (55 lines):

diff -r 105b11e5b2bb -r be079f2379b8 share/man/man4/audio.4
--- a/share/man/man4/audio.4    Sat Mar 28 02:38:15 2020 +0000
+++ b/share/man/man4/audio.4    Sat Mar 28 04:21:58 2020 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: audio.4,v 1.100 2020/03/17 10:50:59 nia Exp $
+.\"    $NetBSD: audio.4,v 1.101 2020/03/28 04:21:58 isaki Exp $
 .\"
 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -27,7 +27,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd March 16, 2020
+.Dd March 28, 2020
 .Dt AUDIO 4
 .Os
 .Sh NAME
@@ -157,6 +157,14 @@
 .Dv AUDIO_ENCODINGFLAG_EMULATED
 are able to
 .Xr mmap 2 .
+.Pp
+The audio device, like most devices, can be used in
+.Xr select 2 ,
+can be set in non-blocking mode and can be set (with a
+.Dv FIOASYNC
+ioctl) to send a
+.Dv SIGIO
+when I/O is possible.
 The mixer device can be set to generate a
 .Dv SIGIO
 whenever a mixer value is changed.
@@ -401,7 +409,7 @@
 are one of the values obtained by
 .Dv AUDIO_GETENC .
 .Va channels
-ranges from 1 to 12 for playback.
+ranges from 1 to 12.
 .Va frequency
 ranges from 1000Hz to 192000Hz.
 .Pp
@@ -811,12 +819,6 @@
 .Sh HISTORY
 Support for virtual channels and mixing first appeared in
 .Nx 8.0 .
-.Sh CAVEATS
-The audio device cannot be reliably used with event notification mechanisms
-such as
-.Xr poll 2 .
-Most users are expected to only read and write a limited number of samples at
-a time, limiting the time spent in the system call.
 .Sh BUGS
 If the device is used in
 .Xr mmap 2