On 04/29/2010 01:58 PM, Kevin Hilman wrote: > Peter Tseng <tsenpet09@xxxxxxxxx> writes: > >> I last posted a few weeks ago; I'm Peter Tseng, using the Gumstix Overo >> for a project. I'm interested in power management and a few related >> things. A few of the things I am interested in are suspend to disk and >> snapshot boot. >> >> I found a page on elinux.org with a few notes on the issue for ARM. >> However, it looks to be a bit outdated: >> http://elinux.org/Suspend_To_Disk_For_ARM >> >> I am wondering how applicable anything on this page is to the current >> omap-pm developments. Or, if not, any pointers on how it might be done - >> for example, if I felt like I should do some hacking to try to get this >> working and contribute these back, a general outline of what I might >> have to do) > > Not really and answer to your question since I don't know the answer, > but just curious about your goals, since there may be an easier way. > > What do you expect to gain from suspend-to-disk + snapshot boot that > you don't already get from suspend-to-RAM using off-mode? > > On OMAP, with off-mode enabled, a suspend to RAM puts the entire OMAP > into full-chip off, and essentially reboots the ARM when waking up > from suspend (or idle) already. > My goals: I am researching very low power devices - the ideal final goal is to make devices such as e-book readers that can last for several months (with regular use) on a single battery charge. The power management capabilities of the OMAP have been helpful, but it does appear (unless I am doing something wrong?) that even with off-mode enabled, a suspend to RAM does still draw a few milliwatts of power. Granted, this isn't much, but when we multiply that over several months, it does add up. So I'd like to know if there's a way to reach zero, hence my earlier questions. Peter -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
