Re: SATA powersave patches

[Pavel Machek <pavel@ucw.cz>]

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
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