Messages in this thread | | | Date | Wed, 09 May 2001 17:08:15 -0400 | From | Jeff Garzik <> | Subject | Re: Patch to make ymfpci legacy address 16 bits |
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Pavel Roskin wrote: > > Hi, Jeff! > > Thanks for your very (!!!) fast response :-) > > > > http://www.red-bean.com/~proski/linux/ymfpci_pm.diff > > > > Why not use pci_driver::{suspend,resume} ? > > I'm just a bit conservative. There are several drivers that don't use this > mechanism, notably trident and maestro. Do you think it's safe to switch > all sound drivers to the mechanism you are proposing? > > I'm worried about a comment in maestro.c: > > /* > * we'd also like to find out about > * power level changes because some biosen > * do mean things to the maestro when they > * change their power state. > */ > > If we switch to pci_driver::{suspend,resume}, will it ever be possible to > add support for any messages other than PM_SUSPEND and PM_RESUME? Probably > yes, but only in the PCI driver dispatches them.
Basically the PCI core should implement what PM is necessary, because eventually struct pci_driver will become a more generic struct driver. When that happens, drivers using pci_driver::{suspend,resume} will automagically work under the new system. To answer your question, the PCI[/driver] core should support messages other than PM_{SUSPEND,RESUME} if they need to be supported. Right now I mostly see suspend/resume implemented and nothing else, so that is a very straightforward conversion to the new PCI API.
Why does maestro.c not use my suggestion? Because it doesn't use struct pci_driver. Why does trident.c not use my suggestion? Only because noone has written and tested the patch for it yet :) It uses struct pci_driver and should be updated to use ::suspend/resume.
> > In ACPI land the kernel should save and restore the PCI device config > > space and the PCI bus config space. It is probably that similar is > > necessary under APM. > > I have never seen any sound driver doing that. I also know that PCI > settings are saved by some BIOSes on some hardware.
That's because full PM support is still very much a work in progress :) The linux-pm-devel sourceforge list has carried recent discussions, as has linux-kernel. Patrick Mochel(sp?) @ Transmeta has posted a hackers-only patch which incorporates my PCI PM work as well as his own ACPI work to do suspend and resume.
-- Jeff Garzik | Game called on account of naked chick Building 1024 | MandrakeSoft | - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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