Add the dev.pcm.%d.polling sysctl and a short description.

Reviewed by:	ru

share/man/man4/pcm.4

@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 26, 2006
+.Dd November 29, 2006
 .Dt SOUND 4
 .Os
 .Sh NAME
@@ -268,6 +268,12 @@ Format for
 mixing.
 All playback paths will be converted to this format before the mixing
 process begins.
+.It Va dev.pcm.%d.polling
+Experimental polling mode support where the driver operates by querying the
+device state on each tick using a
+.Xr callout 9
+mechanism.
+Disabled by default and currently only available for a few device drivers.
 .El
 .Ss Recording Channels
 On devices that have more than one recording source (ie: mic and line),

share/man/man4/snd_atiixp.4

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 28, 2005
+.Dd November 29, 2006
 .Dt SND_ATIIXP 4
 .Os
 .Sh NAME
@@ -52,6 +52,20 @@ bridge driver allows the generic audio driver,
 to attach to ATI IXP audio devices.
 This driver supports 16bit playback and recording, and 32bit native playback
 and recording.
+.Ss Runtime Configuration
+The following
+.Xr sysctl 8
+variables are available in addition to those available to all
+.Xr sound 4
+devices:
+.Bl -tag -width ".Va dev.pcm.%d.polling" -offset indent
+.It Va dev.pcm.%d.polling
+Experimental polling mode, where the driver operates by querying the device
+state on each tick using
+.Xr callout 9 .
+Polling is disabled by default.
+Do not enable it unless you are facing weird interrupt problems or if the
+device cannot generate interrupts at all.
 .Sh HARDWARE
 The
 .Nm

share/man/man4/snd_es137x.4

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd December 15, 2005
+.Dd November 29, 2006
 .Dt SND_ES137X 4
 .Os
 .Sh NAME
@@ -66,6 +66,13 @@ Enables S/PDIF output on the primary playback channel.
 This
 .Xr sysctl 8
 variable is available only if the device is known to support S/PDIF output.
+.It Va dev.pcm.%d.polling
+Experimental polling mode, where the driver operates by querying the device
+state on each tick using
+.Xr callout 9 .
+Polling is disabled by default.
+Do not enable it unless you are facing weird interrupt problems or if the
+device cannot generate interrupts at all.
 .El
 .Sh HARDWARE
 The

share/man/man4/snd_hda.4

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 8, 2006
+.Dd November 29, 2006
 .Dt SND_HDA 4
 .Os
 .Sh NAME
@@ -73,6 +73,21 @@ The HDA specification defines the register-level interface, physical link
 characteristics, codec programming models, and codec architectural components.
 This specification is intended for both device driver developers and hardware
 component designers.
+.Ss Runtime Configuration
+The following
+.Xr sysctl 8
+variables are available in addition to those available to all
+.Xr sound 4
+devices:
+.Bl -tag -width ".Va dev.pcm.%d.polling" -offset indent
+.It Va dev.pcm.%d.polling
+Experimental polling mode, where the driver operates by querying the device
+state on each tick using
+.Xr callout 9 .
+Polling is disabled by default.
+Do not enable it unless you are facing weird interrupt problems or if the
+device cannot generate interrupts at all.
+.El
 .Sh HARDWARE
 The
 .Nm

share/man/man4/snd_via8233.4

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 25, 2006
+.Dd November 29, 2006
 .Dt SND_VIA8233 4
 .Os
 .Sh NAME
@@ -52,6 +52,20 @@ bridge driver allows the generic audio driver,
 to attach to the VIA VT8233 audio devices.
 These audio chipsets are integrated in the southbridge on many VIA based
 motherboards.
+.Ss Runtime Configuration
+The following
+.Xr sysctl 8
+variables are available in addition to those available to all
+.Xr sound 4
+devices:
+.Bl -tag -width ".Va dev.pcm.%d.polling" -offset indent
+.It Va dev.pcm.%d.polling
+Experimental polling mode, where the driver operates by querying the device
+state on each tick using
+.Xr callout 9 .
+Polling is disabled by default.
+Do not enable it unless you are facing weird interrupt problems or if the
+device cannot generate interrupts at all.
 .Sh HARDWARE
 The
 .Nm