On Fri, 22 Aug 2008, Pavel Machek wrote:

quoted text
> Hi!
> 
> > > - suspending has side effects
> > 
> > I'm not sure what you mean by that.  Suspension always has side effects 
> > of one kind or another.
> > 
> > > Suspension in USB has always side effects. That's not true for other
> > > subsystems.
> > 
> > Name one.  At the very least, suspending a device means you can't use
> > it again without first calling the driver's resume method.  That's a 
> > side effect.
> 
> IDE, actually. I don't think it is relevant, but you can do hdparm -y,
> and it will automatically spin up when you try to talk to it next
> time.

It's a matter of definitions...  "hdparm -y" doesn't call the driver's 
suspend method, so in some sense it isn't truly a suspend.

But it's true that some systems can power down more or less
transparently (with restart latency as the only visible side effect).

Alan Stern

--
unsubscribe notice
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/