Messages in this thread | | | Date | Fri, 22 Aug 2008 18:14:51 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [linux-pm] Power management for SCSI |
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On Fri, 22 Aug 2008, Pavel Machek wrote:
> 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
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