Re: Regression from 2.6.26: Hibernation (possibly suspend) broken on Toshiba R500 (bisected)

[Greg KH <greg@kroah.com>]

On Fri, Dec 05, 2008 at 05:55:16PM -0800, Linus Torvalds wrote:
> 
> 
> On Sat, 6 Dec 2008, Rafael J. Wysocki wrote:
> >
> > It only affects the legacy handling, but the non-legacy handling was left
> > untouched.  IOW, the old "default" functions are still there and are being
> > called by the "non-legacy" code (it's only used by USB at the moment, AFAICS).
> 
> Ok.
> 
> > Anyway, I did the test doing it only to the devices which don't have any
> > non-default suspend-resume handling at all and _that_ apparently fixed the
> > problem on my box. :-)
> 
> Which makes sense, btw. Because if you do the pci_save_state() on a device 
> that _does_ have a suspend function, you'll be saving the post-suspend 
> state - ie the device turned off.

I think that is why we did not do it for every device, we didn't want to
touch drivers that already had working suspend calls.

> So yeah, we really can only do the default suspend if the device has no 
> pre-existing suspend function - or we'd need to make sure that all PCI 
> drivers that do have suspend functions would only do the higher-level 
> functionality.

Agreed.

thanks,

greg k-h