Messages in this thread | | | Date | Thu, 24 Aug 2023 14:56:56 +0300 | From | Mika Westerberg <> | Subject | Re: [PATCH 1/3] PCI: Add helper to check if any of ancestor device support D3cold |
| |
Hi,
On Thu, Aug 24, 2023 at 12:46:43PM +0800, Kai-Heng Feng wrote: > In addition to nearest upstream bridge, driver may want to know if the > entire hierarchy can be powered off to perform different action. > > So walk higher up the hierarchy to find out if any device has valid > _PR3.
I'm not entirely sure this is good idea. The drivers should expect that the power will be turned off pretty soon after device enters D3hot. Also _PR3 is not PCI concept it's ACPI concept so API like this would only work on systems with ACPI.
| |