Re: [PATCH 5/5] ACPI: Tie ACPI backlight devices to PCI devices if possible

On Sunday, February 06, 2011, Matthew Garrett wrote:

On Sun, Feb 06, 2011 at 09:35:07PM +0100, Rafael J. Wysocki wrote:

...

...

• acpi_get_parent(device->dev->handle, &acpi_parent);
  

• pdev = acpi_get_pci_dev(acpi_parent);
  

• if (pdev) {
  

• 	parent = &pdev->dev;
  

• 	pci_dev_put(pdev);
  

• }
  

I'm afraid you can't do that or suspend problems will happen.

Ugh. Ok, how can we fix this?

Not nicely, I'm afraid.

One possible way is to use device_pm_move_after() to rearrange the devices in the PM core's suspend list, but that will happen in the video device being suspended before the new parent (and resumed after it) -- of course, the only option is to move the ACPI video device after the new parent.

Thanks, Rafael