[src/trunk]: src/share/man/man4 PR kern/32569: Describe the sysctl variable t...

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

details:   https://anonhg.NetBSD.org/src/rev/693e116b28a7
branches:  trunk
changeset: 348283:693e116b28a7
user:      pho <pho%NetBSD.org@localhost>
date:      Thu Oct 13 13:04:02 2016 +0000

description:
PR kern/32569: Describe the sysctl variable the driver provides

diffstat:

 share/man/man4/auich.4 |  21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)

diffs (45 lines):

diff -r 8db1728b972d -r 693e116b28a7 share/man/man4/auich.4
--- a/share/man/man4/auich.4    Thu Oct 13 11:57:55 2016 +0000
+++ b/share/man/man4/auich.4    Thu Oct 13 13:04:02 2016 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: auich.4,v 1.23 2008/04/30 13:10:53 martin Exp $
+.\"    $NetBSD: auich.4,v 1.24 2016/10/13 13:04:02 pho Exp $
 .\"
 .\" Copyright (c) 2000 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 14, 2006
+.Dd October 13, 2016
 .Dt AUICH 4
 .Os
 .Sh NAME
@@ -46,10 +46,25 @@
 i82801FB (ICH6), i82801GB/GR (ICH7), and Intel 6300ESB.
 The driver also supports SiS 7012, nForce MCP, nForce2 MCP-T,
 nForce3 MCP-T, nForce3 250 MCP-T, nForce4, and AMD 8111.
+.Pp
+The driver provides the following
+.Xr sysctl 8
+read/write variable (when hardware support is available):
+.Bl -tag -width Ds
+.It Va hw.auich0.ac97rate
+Link rate of the device in Hz. The driver automatically measures and
+calculates the correct rate so you usually don't need to change
+this. There is, however, a chance that the driver miscalculates the
+rate especially on an emulated hardware, resulting in an incorrect
+playback pitch. When this happens you need to manually set this
+variable to the correct value. Try
+.Li 48000
+if you don't know the correct value as it is the default link rate.
 .Sh SEE ALSO
 .Xr ac97 4 ,
 .Xr audio 4 ,
-.Xr pci 4
+.Xr pci 4 ,
+.Xr sysctl 8
 .Sh HISTORY
 The
 .Nm