Re: [PATCH] PCI: Set device power state to PCI_D0 for device without native PM support

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Thursday, October 06, 2011, Yinghai Lu wrote:
> On Wed, Oct 5, 2011 at 12:41 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > Hi,
> >>   drivers/pci/pci.c |    3 +++
> >>   1 files changed, 3 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> >> index e9651f0..ca8c82d 100644
> >> --- a/drivers/pci/pci.c
> >> +++ b/drivers/pci/pci.c
> >> @@ -664,6 +664,9 @@ static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
> >>                  error = platform_pci_set_power_state(dev, state);
> >>                  if (!error)
> >>                          pci_update_current_state(dev, state);
> >> +               /* Fall back to PCI_D0 if native PM is not supported */
> >> +               else if (!dev->pm_cap)
> >> +                       dev->current_state = PCI_D0;
> >>          } else {
> >>                  error = -ENODEV;
> >>                  /* Fall back to PCI_D0 if native PM is not supported */
> >>
> >
> > I have some vague memories that we tried that and it broke something.
> 
> Do have any hint for us to dig out the configuration for failing?
> 
> >
> > How thoroughly has it been tested?
> 
> tested in setups with intel cpus from Nehalem.

Can you test it on older hardware too, please?

Rafael