[mythtv-users] Forcing the backend to acpi suspend with a frontend connected

Michael Watson michael at thewatsonfamily.id.au
Sun Sep 25 06:01:31 UTC 2011

On 25/09/2011 15:01, Marc MERLIN wrote:
> [While I read the list, Cc on replies are appreciated]
> I read http://www.mythtv.org/wiki/ACPI_Wakeup and I understand that due to
> old mythtv design, the RTC wakeup code was meant for when the backend is
> physically powered off and rebooted, as opposed to now using suspend to RAM.
> In my case, I do have a recent PC, suspend to RAM is working and if I kill
> mythfrontend on my htpc, then mythtv-backend goes idle and triggers the right
> scripts to suspend to RAM and resumes on its own.
> I also know about mythwelcome.
> But, this is not my question: I just want my htpc to suspend if mythfrontend
> is runnind and nothing is playing after timeout X, or if something is
> playing but paused for more than Y seconds.
> > From what I read, while this would be the desired behaviour with current
> ACPI sleep capable hardware, there is no support in mythfrontend/mythtv-backend
> for that.
> Am I correct?
> If so, I'm looking at 3 solutions
> 1) use strace/lsof to monitor mythfrontend and kill mythfrontend from an
> outside shell script if it meets my definition of idle, which in turn
> will allow mythtv-backend to timeout and trigger ACPI sleep
> 2) Is there a hook into the mythtv-backend idle code where I can could just
> tell it 'go to sleep now' from an outside shell script?
> I realize I can just suspend linux from the shell script, but that will not
> update the RTC clock to wakeup the PC when the next recording is scheduled.
> I do need some way to get mythtv-backend to dump its 'wake up at X' timer in
> my RTC.
> 3) Better even, does more recent mythtv code just allow mythtv-backend to go to
> sleep even if mythfrontend is connected (either when it's not playing at
> all, or if it's been paused for too long)?
> Thanks,
> Marc

On my Frontends, I run XScreensaver and a script via cron that waits for 
the screensaver to be active for X minutes, then shutsdown the machine,  
(or if it is a FE/SBE closes mythfrontend and allows mythwelcome to 
shutdown the machine when the backend is idle).
     I have a 5 Min Delay on xscreensaver, then my script waits for the 
xscreensaver to be active for 15 minutes.  So after 20 Minutes of idle, 
the FE shutdowns automatically.


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