[PATCH] drm/nouveau/acpi: use DSM if bridge does not support D3cold

[Mika Westerberg]

On Fri, Aug 26, 2016 at 01:00:54AM +0200, Peter Wu wrote:
> Even if PR3 support is available on the bridge, it will not be used if
> the PCI layer considers it unavailable (i.e. on all laptops from 2013
> and 2014). Ensure that this condition is checked to allow a fallback to
> the Optimus DSM for device poweroff.
> 
> Initially I wanted to call pci_d3cold_enable before checking bridge_d3
> (in case the user changed d3cold_allowed), but that is such an unlikely
> case and likely fragile anyway. The current patch is suggested by Mika
> in http://www.spinics.net/lists/linux-pci/msg52599.html
> 
> Cc: Mika Westerberg <mika.westerberg at linux.intel.com>

Reviewed-by: Mika Westerberg <mika.westerberg at linux.intel.com>