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Dynamic PM in Jolla

asked 2014-09-02 18:42:12 +0300

marmistrz gravatar image

AFAIK SailfishOS has static PM (due to Android patches). Is it possible to make it use dynamic PM (as our old N900s or N9s)?

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Sorry, what is PM?

magullo ( 2014-09-03 10:18:31 +0300 )edit

@magullo Power Managment

max ( 2014-09-03 13:22:27 +0300 )edit

2 Answers

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answered 2014-09-03 09:34:53 +0300

Philippe De Swert gravatar image

Well it is not impossible. But it will require a huge amount of work and very detailed specs of the chips involved. Not an easy task at all. And definitely not one Jolla has the resources for. (For N900 and N9 Nokia had a huge team of power management engineers and a co-operation with a team from TI)

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Would it mean that if not properly done, it could be much worse than it should? Does Jolla consider switching to Dynamic PM is some (more or less distant future) when the SailfishOS will be more polished, etc.?

marmistrz ( 2014-09-03 17:44:55 +0300 )edit

Will probably never happen because most drivers are not made by Jolla, and I think most of the problem comes from the drivers.

javispedro ( 2014-09-03 18:23:43 +0300 )edit

Well, according to the felipec's post [1], the dynamic pm kernel code is upstream, so the module should be there too. So would it be possible to achieve this by enabling some kernel modules (neglecting the power consumption for the time being)?

[1] http://felipec.wordpress.com/2012/01/04/android-vs-maemo-power-managment-static-vs-dynamic/

marmistrz ( 2014-09-03 19:41:39 +0300 )edit

"the module should be there"? This is not something you just 'plug on'. It's a pervasive change in most device drivers.

javispedro ( 2014-09-04 13:04:14 +0300 )edit

So without the source code of drivers, no one can do anything, can they?

marmistrz ( 2014-09-04 17:10:37 +0300 )edit

answered 2014-09-03 18:22:02 +0300

javispedro gravatar image

updated 2018-01-01 17:10:57 +0300

marmistrz gravatar image

It's more or less trivial to disable "opportunistic suspend", which is the most annoying behaviour of Android-like power management:

mcetool --set-suspend-policy=early

However this won't really move to dynamic PM. Most of the kernel drivers still will depend on the system being suspended in order to disable timers, etc. So your battery life will suffer. Not much in my experience, but not more than 2 days even in low use.

my own daily Jolla is configured like this.

For additional information see http://talk.maemo.org/showthread.php?t=92183 and more specifically the following post: http://talk.maemo.org/showpost.php?p=1401956&postcount=29

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is there a way to have this set on every boot?found a way to do it via http://lukas.zapletalovi.com/2013/08/execute-command-during-start-with-systemd.html

Jeffrey04 ( 2015-08-18 15:15:23 +0300 )edit

It already persists between boots.

javispedro ( 2015-08-18 18:31:48 +0300 )edit

OH~ thx for the info

Jeffrey04 ( 2015-08-20 04:45:53 +0300 )edit
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Asked: 2014-09-02 18:42:12 +0300

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Last updated: Jan 01 '18