[alsa-devel] [PATCH - alsactl 1/1] make systemd service start in proper way

[Takashi Iwai]

On Sun, 24 Jan 2016 13:57:12 +0100,
Tom Yan wrote:
> 
> How do you think the check should be? The symlinks will just be no-op
> if sound.target doesn't exist. I'm not gonna introduce some dirty
> switch to make it fall back to basic.target.wants for systemd<v18.

Well, for example, we may add a check of systemd version in configure
script and gives a warning if it's under v18, at least.  It's very
unlikely that user still runs such an old version, but we still should
be careful and need some excuse for dropping the support.  And this
should be documented explicitly.


thanks,

Takashi

> On 24 January 2016 at 19:32, Takashi Iwai <tiwai at suse.de> wrote:
> > On Sun, 24 Jan 2016 11:48:09 +0100,
> > Tom Yan wrote:
> >>
> >> Since v18:
> >> http://cgit.freedesktop.org/systemd/systemd/commit/?id=88dfa2938af09e511e4911e6984360ded0e2cd8d
> >> http://cgit.freedesktop.org/systemd/systemd/tag/?id=v18
> >
> > OK, it's old enough, but maybe safer to have some check in configure
> > script?
> >
> >
> > Takashi
> >
> >>
> >> On 24 January 2016 at 15:56, Takashi Iwai <tiwai at suse.de> wrote:
> >> > On Sun, 24 Jan 2016 01:30:23 +0100,
> >> > tom.ty89 at gmail.com wrote:
> >> >>
> >> >> From: Tom Yan <tom.ty89 at gmail.com>
> >> >>
> >> >> Use sound.target to trigger the service, which is the proper way
> >> >> to start a service related to sound card. This also makes sure that
> >> >> the service will only start if a sound card exists in the system.
> >> >
> >> > Has this target existed in all released versions of systemd?
> >> > Just to be sure...
> >> >
> >> >> basic.target is too early for either of the service:
> >> >> 1. alsa-state.service will spam "No soundcards found" on every boot
> >> >
> >> > Actually this should be seen as a bug of alsactl itself.  In the
> >> > daemon mode, it should be allowed to run without the sound card at
> >> > start.
> >> >
> >> >> 2. alsa-restore.service will never start because of
> >> >>    "ConditionPathExistsGlob=/dev/snd/control*"
> >> >
> >> > ... unless reloading or starting the service later.
> >> >
> >> >> "After=sysinit.target" is removed from alsa-state.service because it
> >> >> never made any sense.
> >> >>
> >> >> "After=alsa-state.service" is removed from alsa-restore.service because
> >> >> it is completely unnecessary with the daemon conf switch.
> >> >>
> >> >> Now either of serivce is enough to manage the state all by itself without
> >> >> the udev rules if only ONE sound card exists in the system, while the rules
> >> >> are still necessary in system with multiple sound cards.
> >> >
> >> > ... or with a hotplug device.
> >> >
> >> >> "StandardOutput=syslog" is also removed from alsa-restore.service because it
> >> >> makes little sense (if it has ever switched the behaviour away from default).
> >> >
> >> > That's superfluous indeed.
> >> >
> >> >
> >> > thanks,
> >> >
> >> > Takashi
> >> >
> >> >
> >> >> Signed-off-by: Tom Yan <tom.ty89 at gmail.com>
> >> >>
> >> >> diff --git a/alsactl/Makefile.am b/alsactl/Makefile.am
> >> >> index cac8094..90fab9d 100644
> >> >> --- a/alsactl/Makefile.am
> >> >> +++ b/alsactl/Makefile.am
> >> >> @@ -29,8 +29,8 @@ systemdsystemunit_DATA = \
> >> >>
> >> >>  install-data-hook:
> >> >>       $(MKDIR_P) -m 0755 \
> >> >> -             $(DESTDIR)$(systemdsystemunitdir)/basic.target.wants
> >> >> -     ( cd $(DESTDIR)$(systemdsystemunitdir)/basic.target.wants && \
> >> >> +             $(DESTDIR)$(systemdsystemunitdir)/sound.target.wants
> >> >> +     ( cd $(DESTDIR)$(systemdsystemunitdir)/sound.target.wants && \
> >> >>               rm -f alsa-state.service alsa-restore.service && \
> >> >>               $(LN_S) ../alsa-state.service alsa-state.service && \
> >> >>               $(LN_S) ../alsa-restore.service alsa-restore.service)
> >> >> diff --git a/alsactl/alsa-restore.service.in b/alsactl/alsa-restore.service.in
> >> >> index 2884098..fbcf983 100644
> >> >> --- a/alsactl/alsa-restore.service.in
> >> >> +++ b/alsactl/alsa-restore.service.in
> >> >> @@ -6,12 +6,9 @@
> >> >>  [Unit]
> >> >>  Description=Save/Restore Sound Card State
> >> >>  ConditionPathExists=!@daemonswitch@
> >> >> -ConditionPathExistsGlob=/dev/snd/control*
> >> >> -After=alsa-state.service
> >> >>
> >> >>  [Service]
> >> >>  Type=oneshot
> >> >>  RemainAfterExit=true
> >> >>  ExecStart=- at sbindir@/alsactl restore
> >> >>  ExecStop=- at sbindir@/alsactl store
> >> >> -StandardOutput=syslog
> >> >> diff --git a/alsactl/alsa-state.service.in b/alsactl/alsa-state.service.in
> >> >> index f1321d6..5a8fe5e 100644
> >> >> --- a/alsactl/alsa-state.service.in
> >> >> +++ b/alsactl/alsa-state.service.in
> >> >> @@ -6,7 +6,6 @@
> >> >>  [Unit]
> >> >>  Description=Manage Sound Card State (restore and store)
> >> >>  ConditionPathExists=@daemonswitch@
> >> >> -After=sysinit.target
> >> >>
> >> >>  [Service]
> >> >>  Type=simple
> >> >> --
> >> >> 2.7.0
> >> >>
> >>
>