Re: autosuspend for SCSI devices

From: Pavel Machek
Date: Tue Aug 26 2008 - 05:59:34 EST


On Mon 2008-08-25 10:55:44, Oliver Neukum wrote:
> Am Montag 25 August 2008 10:19:01 schrieb Pavel Machek:
> > From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> >
> > Add support for autosuspend/autoresume of the SCSI devices. Lowlevel
> > driver can use it to spin the disk down... and it is neccessary step
> > for powering down the controllers.
> >
> > Spinning down the disk is useful - saves ~0.5W here, and it is last
> > major thing we can do to save power on some small machines like
> > Kohjinsha subnotebooks.
> >
> > Signed-off-by: Pavel Machek <pavel@xxxxxxx>
>
> Hi,
>
> firstly, it doesn't consider error handling before suspending.

What problems do you see with error handling? This patch does not
touch the error handling, and I do not think it needs to touch it.

> Secondly, it is simply not true that in SCSI suspending the disks
> is always necessary before suspending the controller.

Ok, will fix the changelog... but it is still true at least for USB
controllers.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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