[PATCH] PCI / PM / Runtime: Make runtime PM of PCI devices inactive by default

[PATCH] PCI / PM / Runtime: Make runtime PM of PCI devices inactive by default

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Make the run-time power management of PCI devices be inactive by
default by calling pm_runtime_forbid() for each PCI device during its
initialization.  This setting may be overriden by the user space with
the help of the /sys/devices/.../power/control interface.

That's necessary to avoid breakage on systems where ACPI-based
wake-up is known to fail for some devices.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/pci/pci.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6/drivers/pci/pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci.c
+++ linux-2.6/drivers/pci/pci.c
@@ -1540,8 +1540,10 @@ void pci_pm_init(struct pci_dev *dev)
 	int pm;
 	u16 pmc;
 
+	pm_runtime_forbid(&dev->dev);
 	device_enable_async_suspend(&dev->dev);
 	dev->wakeup_prepared = false;
+
 	dev->pm_cap = 0;
 
 	/* find PCI PM capability in list */

Re: [PATCH] PCI / PM / Runtime: Make runtime PM of PCI devices inactive by default

[Jesse Barnes]

On Sat, 27 Feb 2010 21:37:37 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Make the run-time power management of PCI devices be inactive by
> default by calling pm_runtime_forbid() for each PCI device during its
> initialization.  This setting may be overriden by the user space with
> the help of the /sys/devices/.../power/control interface.
> 
> That's necessary to avoid breakage on systems where ACPI-based
> wake-up is known to fail for some devices.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/pci/pci.c |    2 ++
>  1 file changed, 2 insertions(+)
> 
> Index: linux-2.6/drivers/pci/pci.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/pci.c
> +++ linux-2.6/drivers/pci/pci.c
> @@ -1540,8 +1540,10 @@ void pci_pm_init(struct pci_dev *dev)
>  	int pm;
>  	u16 pmc;
>  
> +	pm_runtime_forbid(&dev->dev);
>  	device_enable_async_suspend(&dev->dev);
>  	dev->wakeup_prepared = false;
> +
>  	dev->pm_cap = 0;
>  
>  	/* find PCI PM capability in list */
> 

Applied to my for-linus branch, thanks.

-- 
Jesse Barnes, Intel Open Source Technology Center