On Mon, 16 Nov 2009 03:13:48 -0500 Jeff Garzik <jgarzik@xxxxxxxxx> wrote: > On 11/16/2009 01:14 AM, Tejun Heo wrote: > > Hello, > > > > Arjan van de Ven wrote: > >> sigh. so I moved all the generic logic generic, and left the ahci > >> specific code specific to ahci. I put the logic there where it was > >> easy to implement, and there where the other link power management > >> controls are (in sysfs). If that's not good enough, I'm out of my > >> skills in the libata world to be honest, and would like to ask you > >> to implement that instead. let me know what sysfs looks like and > >> I'll adjust powertop to it.... > > > > The reason why we have sysfs attributes which should have been at > > link layer at host was that it originally was for ahci alpm which > > is host specific feature which got extended to something somewhat > > generic. Now another pm feature which should belong to link is > > added to host following the precedence. > > > > Then again, it's also true that nobody really cares about ATA PM > > features enough during past couple of years so I really don't want > > to prevent the feature you're trying to add. It would be best if > > there's someone who would pick it up and implement proper > > infrastructure but well that doesn't seem to be happening anytime > > soon. > > > > So, I don't know. That's the concern I have but I don't want to > > nack your change either. One thing is at least make those > > functions take ata_link isntead of ata_port as there's nothing port > > specific about those. Jeff, what do you think? > > Well, > > - these are link-level features > - libata lacks a link-level sysfs API > - we need a link-level sysfs API (ata_transport, anyone?) > > The ugly alternative has always been to hack in something at the host > level. is there a hardware way to ask for the link status via a link level thing? I thought the sata_scr_read() was by definition a host thing -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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
