Hi, Smart,
> We can make or modify some driver to "setting" CPU into some state. And the > whole process need no intervention from user mode. IMHO, what you want is measuring the power consumption, so can you use some physic device like power meter to do that? IF you 'SET' CPU into deep c, but you still want to 'check' it by SW, where will your SW run? > We want to know whether moblin has some low level interface or driver which > can make CPU enter some power state. And we can invoke them to set CPU state > which is most like deciding by OS as you mentioned. Moblin is targeting for atom based platform, atom is a X86 arch processor. So in this point, moblin is using almost same (at least in processor related sides) implementation with upstream linux x86 kernel. Moblin's most modification on kernel and driver will back to mainline linux as well. AND if your mentioned power state is pstate, like before email discussion, you can find it; if your mentioned power state is cstate, this kind of driver/interface for your mentioned 'setting' purpose didn't exist. Just my point, maybe misunderstand your scenarios. From: Smart Yang [mailto:[email protected]] Sent: Wednesday, September 16, 2009 2:55 PM To: Zhang, Austin; [email protected]; [email protected] Subject: Re: [Moblin Dev] low power state of atom Hi Austin, We can make or modify some driver to "setting" CPU into some state. And the whole process need no intervention from user mode. We want to know whether moblin has some low level interface or driver which can make CPU enter some power state. And we can invoke them to set CPU state which is most like deciding by OS as you mentioned. Message: 9 Date: Wed, 16 Sep 2009 14:41:59 +0800 From: "Zhang, Austin" <[email protected]> To: ??? <[email protected]>, Arjan van de Ven <[email protected]> Cc: dev <[email protected]> Subject: Re: [Moblin Dev] low power state of atom Message-ID: <38d9f46dff92c54980d2f2c1e8ee313001ab921...@pdsmsx503.ccr.corp.intel.com> Content-Type: text/plain; charset="gb2312" > how can we get this tool.so we can exactly know which C and P states the > system using. > then, > how can we set the CPU into Deeper sleep?like pxa270?we can change cpu > mode by writting cp15 register > > we check the datasheet of both z5xx and SCH(us15wx) ,but find no > description of how can we generate the signals which can force CPU enter > Deeper sleep. Why not google :) http://www.lesswatts.org/projects/powertop/ Again, like arjan said, when you are trying to 'setting' it, that means your cpu is working, so at this kind of situation, you CAN NOT enter into deep c because cpu is working to your task. Please let OS/CPU decide when and which level it should go to rather than 'setting' it. > my purpose is to check the cpu Actual power loss when cpu work in Deeper > sleep(C4)?or Deep power down(C6)?. Maybe you should use some physical device like power meter rather than by 'setting something and check it' for this purpose. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of ??? Sent: Wednesday, September 16, 2009 2:20 PM To: Arjan van de Ven Cc: dev Subject: Re: [Moblin Dev] low power state of atom Hi? thanks for your answer? first? ?I suspect that your system WILL go into C4. If you are not sure, you can run the powertop tool,?how can we get this tool.so we can exactly know which C and P states the system using. then, how can we set the CPU into Deeper sleep?like pxa270?we can change cpu mode by writting cp15 register we check the datasheet of both z5xx and SCH(us15wx) ,but find no description of how can we generate the signals which can force CPU enter Deeper sleep. _______________________________________________ Moblin dev Mailing List [email protected] To manage or unsubscribe from this mailing list visit: http://lists.moblin.org/listinfo/dev or your user account on http://moblin.org once logged in. For more information on the Moblin Developer Mailing lists visit: http://moblin.org/community/mailing-lists
