* sleep / wake-up @ 2006-06-10 18:39 Guennadi Liakhovetski 2006-06-10 22:03 ` Jon Scully 0 siblings, 1 reply; 7+ messages in thread From: Guennadi Liakhovetski @ 2006-06-10 18:39 UTC (permalink / raw) To: linuxppc-embedded Hi all, This is a complete newbie question - just like I am on powerpc. How does one put to sleep / wake up an embedded ppc (mpc8241) system? Notice, I've never done it (sleep / suspend) on x86 either, and I only have a VERY vague idea of what it's all about... But I'd read if I knew what and where - half an hour googleing didn't bring any positive results apart from links to pbbuttonsd, which mainly describes ppc / apple notebooks. What I'd like to know is a bit of theory - kernel-level support and user-level utilities, as well as what one does practically to put a ppc to sleep / wake it up. Thanks Guennadi --- Guennadi Liakhovetski ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: sleep / wake-up 2006-06-10 18:39 sleep / wake-up Guennadi Liakhovetski @ 2006-06-10 22:03 ` Jon Scully 2006-06-10 22:41 ` Guennadi Liakhovetski 0 siblings, 1 reply; 7+ messages in thread From: Jon Scully @ 2006-06-10 22:03 UTC (permalink / raw) To: linuxppc-embedded [-- Attachment #1: Type: text/plain, Size: 1062 bytes --] Also, here's an article (just about 4 days old): http://www.linux.com/article.pl?sid=06/05/24/1716222 (I thought the subject sounded familiar ;-) On 6/10/06, Guennadi Liakhovetski <g.liakhovetski@gmx.de> wrote: > > Hi all, > > This is a complete newbie question - just like I am on powerpc. How does > one put to sleep / wake up an embedded ppc (mpc8241) system? Notice, I've > never done it (sleep / suspend) on x86 either, and I only have a VERY > vague idea of what it's all about... But I'd read if I knew what and where > - half an hour googleing didn't bring any positive results apart from > links to pbbuttonsd, which mainly describes ppc / apple notebooks. > > What I'd like to know is a bit of theory - kernel-level support and > user-level utilities, as well as what one does practically to put a ppc to > sleep / wake it up. > > Thanks > Guennadi > --- > Guennadi Liakhovetski > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > [-- Attachment #2: Type: text/html, Size: 1553 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: sleep / wake-up 2006-06-10 22:03 ` Jon Scully @ 2006-06-10 22:41 ` Guennadi Liakhovetski 2006-06-10 23:02 ` Lee Revell 0 siblings, 1 reply; 7+ messages in thread From: Guennadi Liakhovetski @ 2006-06-10 22:41 UTC (permalink / raw) To: Jon Scully; +Cc: linuxppc-embedded On Sat, 10 Jun 2006, Jon Scully wrote: > Also, here's an article (just about 4 days old): > http://www.linux.com/article.pl?sid=06/05/24/1716222 > (I thought the subject sounded familiar ;-) Ok, thanks for both replies. That's a good start already! But this is all about __software__ suspend. But aren't some other "hardware" suspend-modes also available on ppc, like suspend-to-RAM? For example, on my system I could say quite a bit of power by stopping the HD, switching off USB-ports, eth, and then putting the CPU to sleep? Would all this be doable by just performing those steps and then clocking the CPU down? I must admit, I don't understand the whole idea behind suspending at all. What happens to all applications that went to sleep for 1 second and wake up 2 days later? What about all network connections? timeouts? I have to read some basics... Thanks Guennadi --- Guennadi Liakhovetski ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: sleep / wake-up 2006-06-10 22:41 ` Guennadi Liakhovetski @ 2006-06-10 23:02 ` Lee Revell 2006-06-10 23:38 ` Guennadi Liakhovetski 0 siblings, 1 reply; 7+ messages in thread From: Lee Revell @ 2006-06-10 23:02 UTC (permalink / raw) To: Guennadi Liakhovetski; +Cc: linuxppc-embedded On Sun, 2006-06-11 at 00:41 +0200, Guennadi Liakhovetski wrote: > On Sat, 10 Jun 2006, Jon Scully wrote: > > > Also, here's an article (just about 4 days old): > > http://www.linux.com/article.pl?sid=06/05/24/1716222 > > (I thought the subject sounded familiar ;-) > > Ok, thanks for both replies. That's a good start already! But this is all > about __software__ suspend. But aren't some other "hardware" suspend-modes > also available on ppc, like suspend-to-RAM? For example, on my system I > could say quite a bit of power by stopping the HD, switching off > USB-ports, eth, and then putting the CPU to sleep? Would all this be > doable by just performing those steps and then clocking the CPU down? > Did you read the article? "ACPI state S3 -- also know as Suspend-to-RAM -- is the state where everything in the system enters a low-power state except for RAM, which consumes a small amount of power in order to retain its contents, so that upon resuming, everything is loaded back from the memory and all running applications are restored immediately." > I must admit, I don't understand the whole idea behind suspending at all. > What happens to all applications that went to sleep for 1 second and wake > up 2 days later? What about all network connections? timeouts? I have to > read some basics... It's insanely difficult and complicated. Every single driver and kernel subsystem has to be changed. Zillions of man-hours have gone into getting suspend to work on Linux and it's still not there... Lee ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: sleep / wake-up 2006-06-10 23:02 ` Lee Revell @ 2006-06-10 23:38 ` Guennadi Liakhovetski 2006-06-11 0:05 ` Lee Revell 0 siblings, 1 reply; 7+ messages in thread From: Guennadi Liakhovetski @ 2006-06-10 23:38 UTC (permalink / raw) To: Lee Revell; +Cc: linuxppc-embedded On Sat, 10 Jun 2006, Lee Revell wrote: > On Sun, 2006-06-11 at 00:41 +0200, Guennadi Liakhovetski wrote: > > On Sat, 10 Jun 2006, Jon Scully wrote: > > > > > Also, here's an article (just about 4 days old): > > > http://www.linux.com/article.pl?sid=06/05/24/1716222 > > > (I thought the subject sounded familiar ;-) > > > > Ok, thanks for both replies. That's a good start already! But this is all > > about __software__ suspend. But aren't some other "hardware" suspend-modes > > also available on ppc, like suspend-to-RAM? For example, on my system I > > could say quite a bit of power by stopping the HD, switching off > > USB-ports, eth, and then putting the CPU to sleep? Would all this be > > doable by just performing those steps and then clocking the CPU down? > > > > Did you read the article? > > "ACPI state S3 -- also know as Suspend-to-RAM -- is the state where > everything in the system enters a low-power state except for RAM, which > consumes a small amount of power in order to retain its contents, so > that upon resuming, everything is loaded back from the memory and all > running applications are restored immediately." Yes: "ACPI" - we are talking about a (embedded) PPC... But I thought you could "simulate" that without ACPI too. AFAIU, ACPI is the way hardware (motherboard / laptop) manufacturers tell you about system's configuration, including how to enter S3. In its absence suspending every (e.g., embedded) system you have to _know_ the hardware. E.g., what do they do on Apple ppc laptops? You don't have ACPI there. Is there any generic system there or did they just study every new ppc-mac and handled it specially? > > I must admit, I don't understand the whole idea behind suspending at all. > > What happens to all applications that went to sleep for 1 second and wake > > up 2 days later? What about all network connections? timeouts? I have to > > read some basics... > > It's insanely difficult and complicated. Every single driver and kernel > subsystem has to be changed. Zillions of man-hours have gone into > getting suspend to work on Linux and it's still not there... I guess, I really wanted to ask about IO operations in the fly... probably, you only use automatic suspend if you know your system is not supposed to do any long IO-operations, and "short" ones will be completed? Even if you monitor loadavg - it might stay quite low during a long transfer. And if you do long IOs you have to decide when it is safe to suspend yourself... So that the kernel just has to flush current IO queues... Yeah, doesn't sound very easy. Thanks Guennadi --- Guennadi Liakhovetski ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: sleep / wake-up 2006-06-10 23:38 ` Guennadi Liakhovetski @ 2006-06-11 0:05 ` Lee Revell 2006-06-11 10:57 ` Guennadi Liakhovetski 0 siblings, 1 reply; 7+ messages in thread From: Lee Revell @ 2006-06-11 0:05 UTC (permalink / raw) To: Guennadi Liakhovetski; +Cc: linuxppc-embedded On Sun, 2006-06-11 at 01:38 +0200, Guennadi Liakhovetski wrote: > > Yes: "ACPI" - we are talking about a (embedded) PPC... But I thought > you could "simulate" that without ACPI too. AFAIU, ACPI is the way > hardware (motherboard / laptop) manufacturers tell you about system's > configuration, including how to enter S3. In its absence suspending > every (e.g., embedded) system you have to _know_ the hardware. E.g., > what do they do on Apple ppc laptops? You don't have ACPI there. Is > there any generic system there or did they just study every new > ppc-mac and handled it specially? It seems that PPC Macs have a hardware PMU: http://www.resexcellence.com/linux_icebox/01-31-02.shtml And that some embedded devices handle this at the hardware level with no OS support needed: http://ozlabs.org/pipermail/linuxppc-dev/2001-February/010179.html So AFAICT there's no standard like ACPI - each board does it differently. Lee ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: sleep / wake-up 2006-06-11 0:05 ` Lee Revell @ 2006-06-11 10:57 ` Guennadi Liakhovetski 0 siblings, 0 replies; 7+ messages in thread From: Guennadi Liakhovetski @ 2006-06-11 10:57 UTC (permalink / raw) To: Lee Revell; +Cc: linuxppc-embedded On Sat, 10 Jun 2006, Lee Revell wrote: > It seems that PPC Macs have a hardware PMU: > > http://www.resexcellence.com/linux_icebox/01-31-02.shtml > > And that some embedded devices handle this at the hardware level with no > OS support needed: > > http://ozlabs.org/pipermail/linuxppc-dev/2001-February/010179.html > > So AFAICT there's no standard like ACPI - each board does it > differently. Right, so, without such support in the hardware or without the appropriate information all you can do is software suspend-to-disk, I think. That's for sleep-states. And just for power-saving you can switch various parts off in subsystem-specific ways (e.g., spin down a IDE hd), clock the CPU down, but still keep your system __running__, i.e. all processes run just as usual only slower. Thanks Guennadi --- Guennadi Liakhovetski ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2006-06-11 10:57 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2006-06-10 18:39 sleep / wake-up Guennadi Liakhovetski 2006-06-10 22:03 ` Jon Scully 2006-06-10 22:41 ` Guennadi Liakhovetski 2006-06-10 23:02 ` Lee Revell 2006-06-10 23:38 ` Guennadi Liakhovetski 2006-06-11 0:05 ` Lee Revell 2006-06-11 10:57 ` Guennadi Liakhovetski
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