On Tue 2008-02-26 10:52:36, Mark Lord wrote: > Pavel Machek wrote: >> Hi! >> >>>> This is a patch (very ugly, assumes you have just one disk) to bring >>>> powersaving to AHCI. You need Alan's SCSI autosuspend (attached) patch >>>> as a base. >>>> >>>> It saves .5W compared to config with disk spinning, and even .15W >>>> compared to hdparm -y... on my thinkpad x60 anyway. >>> .. >>> >>> There was a discussion of this here today. >> >> Real-life discussion, or something I could read? :-). >> >>> It makes good use of AHCI-specific features. >>> >>> Has it been tested with a Port-Multiplier yet? >> >> I do not know what port-multiplier is, sorry. But it was not really >> tested. It is not expected to work on any other config than notebook >> very similar to mine. >> >>> This is cool enough that we really ought to do a hardware-independent >>> version, so that all SATA interfaces could benefit. Especially ata_piix, >>> but others too. >> >> Well, it seems like it is 10 lines per driver once Alan's SCSI >> autosuspend patches are in... > .. > > Cool (literally)! > > I think I might have gotten your patch confused in my mind > with another AHCI patch, which uses features of the chip itself > to automatically negotiate/change link power status on the fly > (no s/w needed, other than to turn it on). > > That one is very ACPI specific, though. Yep, I seen that, too. I'm just afraid to check, maybe AHCI powerdown does not save that much power when links in powersave already... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
