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

[Huang Ying <ying.huang@intel.com>]

On Wed, 2012-11-07 at 15:30 +1000, Dave Airlie wrote:
> So I've been adding runtime pm to nouveau/radeon, and on X start it does a
> lot of pci accesses. Now because the pm on these devices is equivalent
> to D3cold, we have to resume them which involves a heavy latency due to
> POSTing the cards. The driver configures the autosuspend timeout to 5s for
> this reason, and I think the PCI layer config accesses should respect
> the autosuspend.
> 
> 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.

Best Regards,
Huang Ying