From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mustang.oldcity.dca.net (mustang.oldcity.dca.net [216.158.38.3]) by ozlabs.org (Postfix) with SMTP id D01F867C83 for ; Sun, 11 Jun 2006 09:08:49 +1000 (EST) Subject: Re: sleep / wake-up From: Lee Revell To: Guennadi Liakhovetski In-Reply-To: References: <53107f6e0606101503x4f84cbc0j6f92c601fa464c36@mail.gmail.com> Content-Type: text/plain Date: Sat, 10 Jun 2006 19:02:10 -0400 Message-Id: <1149980531.14253.92.camel@mindpipe> Mime-Version: 1.0 Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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