[Pm-utils] Re: Better integration with power management scripts

[Rafael J. Wysocki]

On Monday 01 May 2006 20:54, Peter Jones wrote:
> On Mon, 2006-05-01 at 20:12 +0200, Stefan Seyfried wrote:
> > On Mon, May 01, 2006 at 10:26:35AM -0400, Peter Jones wrote:
> > > On Fri, 2006-04-28 at 19:56 +0200, Rafael J. Wysocki wrote:
> > > 
> > > > There are some short-term benefits.  For example, we are able to use the RSA
> > > > for encryption and we support suspend-to-disk-and-RAM on some machines
> > > > with the ability to reinitialize the graphics card if necessary.
> > > 
> > > We already have that without it being in userland.
> > 
> > No. Encryption and write-image-to-disk-but-then-suspend-to-ram are only
> > possible with uswsusp (and suspend2).
> 
> Sorry for being vague; I was referring to the graphics reinitialization.

If you think of suspend to RAM alone, you can use some additional userland
tools before suspend/after resume to get your graphics to work.  However for
suspending to disk and _then_ to RAM, you need to integrate these additional
tools with the suspending utility, because you can't touch frozen filesystems
after the STD image has been saved (eg. you can't run a program from any of
them).

> > > > I'm going to implement the ability to cancel the suspend (ie. cancel the image
> > > > saving).  That should be easy in the user space. ;-)
> > > 
> > > Not quite sure... how does this help?
> > 
> > Well, everybody seems to want that feature. It looks like lots of people
> > trigger a suspend, but change their mind afterwards ;-)
> 
> It just seems weird to me.  Suspending should be quick enough that
> canceling it isn't a practical thing to actually do.

We are talking about suspend to disk in which case you have to save the image
and that takes quite some time, even on modern hardware.  There's plenty of
time to press Ctrl+C if need be. :-)

Greetings,
Rafael