alsamixer auto-mute 未关闭，重启后静音

分类：System 标签：Alsa Audio

Arch 下的 alsamixer 声音设置好后，重启又重新变为静音，好奇怪。

开始还在纠结是 alsa 服务的问题，纯属自扰。杯具在于：

alsamixer 中的 Auto-Mute M 选项没有 Disable 掉，关闭 自动静音 就 Ok 了。百文不如一见：

alsamixer auto-mute disabled

南辕北辙

systemctl 查看 alsa 服务状态，虽然都是加载了，但状态却是 dead 有些猫腻，就接着探究

· systemctl status alsa-state.service
alsa-state.service - Manage Sound Card State (restore and store)
   Loaded: loaded (/usr/lib/systemd/system/alsa-state.service; static)
   Active: inactive (dead)

Aug 03 19:39:07 systemd[1]: Started Manage Sound Card State (restore and store).

· systemctl status alsa-store.service
alsa-store.service - Store Sound Card State
   Loaded: loaded (/usr/lib/systemd/system/alsa-store.service; static)
   Active: inactive (dead)

Aug 03 17:13:49 systemd[1]: Started Store Sound Card State.

· systemctl status alsa-restore.service
alsa-restore.service - Restore Sound Card State
   Loaded: loaded (/usr/lib/systemd/system/alsa-restore.service; static)
   Active: inactive (dead) since Sat 2013-08-03 19:39:07 CST; 48min ago
  Process: 271 ExecStart=/usr/bin/alsactl restore (code=exited, status=0/SUCCESS)

Aug 03 20:52:30 systemd[1]: Starting Restore Sound Card State...

尝试启动服务 systemctl 执行 enable 提示说，不能安装：

$ sudo systemctl enable alsa-restore.service
The unit files have no [Install] section. They are not meant to be enabled using systemctl.
Possible reasons for having this kind of units are:
1) A unit may be statically enabled by being symlinked from another unit's
   .wants/ or .requires/ directory.
2) A unit's purpose may be to act as a helper for some other unit which has
   a requirement dependency on it.
3) A unit may be started when needed via activation (socket, path, timer,
   D-Bus, udev, scripted systemctl call, ...).

https://bbs.archlinux.org/viewtopic.php?id=146794

上面这篇帖子提到 static 状态是，以及 alsa store / restore 服务的链接文件都存在：

· systemctl list-unit-files --type=service | grep alsa
alsa-restore.service                        static
alsa-state.service                          static
alsa-store.service                          static

 · systemctl is-enabled alsa-store.service alsa-restore.service
 static
 static

https://bbs.archlinux.org/viewtopic.php?id=147964

然后又科普了一下 static 状态：其他 unit 依赖该服务时会启动它，或是手动启动

static units are those which cannot be enabled/disabled, but it doesn’t mean they are always executed. They will only if another unit depends on them, or if they are manually started.

从 status 的日志中也可以看出来，开机的时候服务有启动过的。虽然无声和 systemctl 没半毛钱关系。 分析的这一陀，绕了弯子，但至少科普了下 systemctl 的 static 服务状态。


本文标题alsamixer auto-mute 未关闭，重启后静音
原始链接https://lvii.github.io/system/2013-08-03-alsamixer-auto-mute/