From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [RFC 3/3] Runtime PM support for named power states Date: Sun, 9 Oct 2005 22:15:34 +0200 Message-ID: <20051009201534.GC11389@openzaurus.ucw.cz> References: <20051008170017.GC10865@openzaurus.ucw.cz> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============88425555367088426==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: Alan Stern Cc: David Brownell , Linux-pm mailing list , Pavel Machek List-Id: linux-pm@vger.kernel.org --===============88425555367088426== Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi! > > I think they need to go in one-after-one, anyway... Adding parameter > > to resume() should definitely be separate patch, because it needs to > > change all drivers *at once*. Removing power_state usage can be > > done incrementally... > > I suppose it could be done like that. It would mean keeping the > power_state member in the structure until all the drivers are updated, > even though the core wouldn't use it any more. Yes... small price for being able to fix stuff incrementally. > Another question: Initially most drivers won't set up an array of named > states. We could have the core treat such devices as though they were > using a generic two-entry array: "on" and "suspend". That would provide > by default essentially the same functionality we have now, and it would > allow many drivers to use the new runtime PM scheme with (almost) no > changes. Do you see anything wrong with that? It will be broken for most existing drivers, anyway... I'd only enable it if driver provided states. > Third question: Is there a usable PCI core routine for choosing power > states? If not, should a PCI ->suspend method usually use the > lowest-power available state? I have a feeling this should involve ACPI, > but it looks like the code hasn't been written yet. pci_choose_state()? It even has some acpi hooks. Pavel -- 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms --===============88425555367088426== Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline --===============88425555367088426==--