Re: SATA powersave patches

From: Pavel Machek
Date: Tue Nov 21 2006 - 18:08:17 EST


Hi!

> >>If I understood correctly, the high power consumption of
> >>ahci controller can be solved by dynamically turning off
> >>command processing while the controller is idle, which
> >>fits nicely into link powersaving, right? So, I think
> >>full-fledged leveled dynamic PM would be an overkill for
> >>this particular problem, but then again, maybe the
> >
> >It is single bit, and it should not even need a timeout, AFAICT, so
> >perhaps we should just fix it (no need for dynamic PM layers). It
> >probably does not even need to be configurable...
>
> I think this has been discussed in linux-ide recently but just to add my
> 2 cents. ALPE and ASP can cause quite some problems. Many devices
> don't implement link powermanagement mode properly and some locks up

Ok, so it needs to be optional :-). I played with the code a little
bit, but did not find combination that both worked and saved power :-(.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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