Correct PCI suspend and resume operations [ was Re: cirrus ich3 doesn't work after suspend to disk ]

[Mark Santcroos]

On Tue, Jun 10, 2003 at 09:44:36AM -0700, Orion Hodson wrote:
> It looks like the pci configuration space state has been lost during
> the suspend and resume.  This may be because the bus has removed power
> from the devices attached to it on suspend.

For sure, in S4 mode the devices are powered down totally.

> I've been through a cross section of drivers this morning and some
> explicitly save and restore the PCI configuration state space and
> others don't.  The former seems like the safest path in most cases.

Yes, it is absolutely necessary even. (For the reason stated above)

> AFAICT, we don't common code for handling this and maybe there should
> be some rather than have each driver replicate this behaviour.

In general, that would of course be better. However, I don't know if the
PCI layer (in this case) always knows enough.
On the other side, if the device itself has to do some special things, the
PCI layer could at least do the generic stuff.
(Warner, will this also be covered by the stuff you are doing?)

Mark

-- 
Mark Santcroos                    RIPE Network Coordination Centre
http://www.ripe.net/home/mark/    New Projects Group/TTM