Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: PCI PM: Restore standard config registers of all devices early | Date | Mon, 2 Feb 2009 18:20:19 +0100 |
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On Monday 02 February 2009, Benjamin Herrenschmidt wrote: > On Mon, 2009-01-26 at 19:04 +0000, Linux Kernel Mailing List wrote: > > Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=aa8c6c93747f7b55fa11e1624fec8ca33763a805 > > Commit: aa8c6c93747f7b55fa11e1624fec8ca33763a805 > > Parent: 0db29af1e767464d71b89410d61a1e5b668d0370 > > Author: Rafael J. Wysocki <rjw@sisk.pl> > > AuthorDate: Fri Jan 16 21:54:43 2009 +0100 > > Committer: Jesse Barnes <jbarnes@virtuousgeek.org> > > CommitDate: Fri Jan 16 12:57:58 2009 -0800 > > > > PCI PM: Restore standard config registers of all devices early > > This seems to break resume on some PowerBooks (just reported by > Andreas).
Yes, I saw the report in Bugzilla.
> I'm not yet sure what's up, but I can imagine various problems with the > approach. For one, pci_enable_device() is the only place where the arch > has a hook to turn back on things like clocks etc... to a device. You > aren't supposed to touch at the config space before the arch got a > chance to turn things back on. I agree there's somewhat a chicken and > egg problem here, so we might need to look more closely at what that > restore thing does and maybe add a call to the arch low level enable > hook first... Or create a new hook.
I'd prefer to create a new hook, althouth there may be a problem with ACPI vs interrupts off. In the meantime, I'd like to test some recent fixes on top of this patch and try a couple of debug patches to see what's up (in the Bugzilla if that's not a problem).
> I don't know how x86 does but I'm sure there must be some kind ACPI > thingy that must be called too before you can touch a device, in case it > got powered off by more than just the standard D states (ie, clock > stopped on the bus or whole power plane switched off). > > I'll try to reproduce and think about it more, but it looks to me that > this patch might not be quite the right approach yet.
Yeah.
Well, the approach is a bit x86-ish ...
Thanks, Rafael
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