Re: [PATCH] pci/runtime-pm: respect devices autosuspend timeout on config access

[David Airlie <airlied@redhat.com>]

> > 
> > Cc: Huang Ying <ying.huang@intel.com>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Rafael J. Wysocki <rjw@sisk.pl>
> > Signed-off-by: Dave Airlie <airlied@redhat.com>
> > ---
> >  drivers/pci/pci-sysfs.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> > index 02d107b..12d3d52 100644
> > --- a/drivers/pci/pci-sysfs.c
> > +++ b/drivers/pci/pci-sysfs.c
> > @@ -487,7 +487,7 @@ pci_config_pm_runtime_put(struct pci_dev *pdev)
> >  	struct device *dev = &pdev->dev;
> >  	struct device *parent = dev->parent;
> >  
> > -	pm_runtime_put(dev);
> > +	pm_runtime_put_autosuspend(dev);
> >  	if (parent)
> >  		pm_runtime_put_sync(parent);
> >  }
> 
> I think you do not need that.  You can implement timeout
> in .runtime_idle callback of the driver.

If I understand what you are suggesting, I should setup some kinda of timer callback to later call suspend, but that seems pointless for me if we have the autosuspend mechanism in place.

Won't I end up racing my timer against other pm stuff? I'm not really runtime pm expert so maybe I'm just missing something.

Dave.