On Mon, Dec 4, 2023 at 7:07 AM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:
>
> If pci_d3cold_enable() or pci_d3cold_disable() is called on a root
> port it is ignored because there is no upstream bridge.
The kerneldoc comment of pci_bridge_d3_update() explains what that
function is for which also covers why it does not take effect when
called on root ports.
> If called on a root port, use `no_d3cold` variable to decide policy
It is unclear that this is about pci_bridge_d3_possible() which
applies to both D3hot and D3cold, not just D3cold AFAICS. I don't
think that no_d3cold should affect the D3hot behavior.
> and also immediately refresh whether D3 is possible.
Which isn't correct AFAICS.
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> drivers/pci/pci.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 72505794cc72..3d4aaecda457 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3023,6 +3023,9 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
> if (pci_bridge_d3_disable)
> return false;
>
> + if (bridge->no_d3cold)
> + return false;
> +
> /*
> * Hotplug ports handled by firmware in System Management Mode
> * may not be put into D3 by the OS (Thunderbolt on non-Macs).
> @@ -3098,7 +3101,11 @@ void pci_bridge_d3_update(struct pci_dev *dev)
> bool d3cold_ok = true;
>
> bridge = pci_upstream_bridge(dev);
> - if (!bridge || !pci_bridge_d3_possible(bridge))
> + if (!bridge) {
> + dev->bridge_d3 = pci_bridge_d3_possible(dev);
> + return;
> + }
> + if (!pci_bridge_d3_possible(bridge))
> return;
>
> /*
> --
> 2.34.1
>
>
