On Thu, 2011-11-03 at 22:30 +0800, Tejun Heo wrote: > Hello, > > On Thu, Nov 3, 2011 at 7:21 AM, Lin Ming <ming.m.lin@xxxxxxxxx> wrote: > >> * How much does this add on top of hardware timed auto spindown and > >> dynamic link power management? > > > > Sorry, I don't understand this question. > > What do you mean? > > I was curious about the amount of additional power saving on top of > the existing PM features. I'll measure the power saving. > > >> * Do the added benefits justify yet another runtime powersaving > >> mechanism? > > > > There will be ACPI firmware which supports ata port runtime D3Cold. > > To enable ata port runtime PM is the first step. > > libata can already turn off unused ports although it wouldn't go as > far as putting the whole controller into D3. At runtime? Could you point me which piece of code implement this? > > >> * Any way we can tie the other stuff with overall runtime PM? > > > > What's the other stuff? > > Do you mean tie disk/link/port/controller stuff with overall runtime PM? > > Hardware initiated spin-down (hdparm -S) and link power saving (look > for ata_lpm_*). It would be great if there's an overall design how > they interact before adding yet another PM vector. Yes. Need to think about it. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
