misc/101268: [patch] /etc/rc.d/mixer should obey mixer_enable rc.conf(5) variable

[Eugene Grosbein]

>Number:         101268
>Category:       misc
>Synopsis:       [patch] /etc/rc.d/mixer should obey mixer_enable rc.conf(5) variable
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Wed Aug 02 15:50:13 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Eugene Grosbein
>Release:        FreeBSD 6.1-STABLE i386
>Organization:
Svyaz Service JSC
>Environment:
System: FreeBSD grosbein.pp.ru 6.1-STABLE FreeBSD 6.1-STABLE #5: Tue Jul 25 20:15:31 KRAST 2006 eu at grosbein.pp.ru:/mnt/tmp/obj/usr/local/src/sys/DADV i386
	i975XBX motherboard with onboard Intel HDA (azalia)

>Description:
	There is no way to prevent /etc/rc.d/mixer from working
	when it sees /dev/mixer* device nodes. However, there may be
	reasons to disable it. For example, i975XBX onboard audio is
	currently not supported by sound(4) audio device infrastructure.
	One can use OSS drivers to make it work but /usr/sbin/mixer
	used by /etc/rc.d/mixer cannot work with OSS's /dev/mixer* nodes.
	Hence, /etc/rc.d/mixer issues lots of errors while running
	and should be disabled.

>How-To-Repeat:
	Boot FreeBSD 6.1 using i975XBX motherboard,
	install and activate OSS driver for onboard audio.
	/etc/rc.d/mixer will see /dev/mixer* devices at shutdown time
	and will try to work with them (hopelessly).

	The following patch introduces the "mixer_enable" rc.conf(5)
	variable that defaults to the value "YES". One may use
	mixer_enable="NO" to disable stock mixer management
	and use compatible version, if any.

>Fix:

--- src/etc/rc.d/mixer.orig	Fri Feb 17 19:30:14 2006
+++ src/etc/rc.d/mixer	Wed Aug  2 23:27:23 2006
@@ -38,6 +38,7 @@
 start_cmd="mixer_start"
 reload_cmd="mixer_start"
 extra_commands="reload"
+: ${mixer_enable:=YES}
 
 #
 # List current mixer devices to stdout.
@@ -81,6 +82,7 @@
 {
 	local mixer
 
+	checkyesno mixer_enable || return
 	for mixer in `list_mixers`; do
 		mixer_restore ${mixer}
 	done
@@ -93,6 +95,7 @@
 {
 	local mixer
 
+	checkyesno mixer_enable || return
 	for mixer in `list_mixers`; do
 		mixer_save ${mixer}
 	done

>Release-Note:
>Audit-Trail:
>Unformatted: