Re: So, what's the status on the recent patches here?

Scott E. Preece
2006-08-31T15:14:30Z

| From: Pavel Machek<pavel@suse.cz>
| ...
| > I'm not sure how you distinguish between a "system" sleep state
| > and a "CPU" sleep state - seems like there's a collection of
| > things that can be shut down or not; except for true OFF, there's
| > always something on.
|
| Well, even in "true OFF", RTC keeps ticking. And in "disk" state
| (swsusp), machine is basically "true OFF" but it still retains state.
---

In our sleep state (which I would aligned with "mem", in the previous
list), the application processor part of the system is basically true
off, but retains state in memory. In our systems, of course, there's a
second processor that is independently going in and out of its own
low-power modes while waking up every so many milliseconds to stay
camped on a cellular network.

One "interesting" diffference between "disk" and "mem" (as we would use
them, though we don't have a disk, so we don't have a "disk" state), is
that suspend-to-disk today requires rebooting, while suspend-to-RAM
doesn't. I don't see why that distinction can't still be below the
interface abstraction presented to a user-space power manager, but it's
the most qualitative difference across the range of proposed operating
points...

scott
--
scott preece
motorola mobile devices, il67, 1800 s. oak st., champaign, il 61820
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