PCI: Consolidate conditions to allow runtime PM on PCIe ports

The conditions to allow runtime PM on PCIe ports are currently spread
across two different files:  The condition relating to hotplug ports is
located in portdrv_pci.c whereas all other conditions are located in pci.c.

Consolidate all conditions in a single place in pci.c, thus making it
easier to follow the logic and amend conditions down the road.

Note that the condition relating to hotplug ports is inserted *before* the
condition relating to the "pcie_port_pm=force" command line option, so
runtime PM is not afforded to hotplug ports even if this option is given.
That's exactly how the code behaved up until now.  If this is not desired,
the ordering of the conditions can simply be reversed.

No functional change intended.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 720f7e27c3a8..a40ba0225265 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2243,6 +2243,17 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
 	case PCI_EXP_TYPE_DOWNSTREAM:
 		if (pci_bridge_d3_disable)
 			return false;
+
+		/*
+		 * Hotplug interrupts cannot be delivered if the link is down,
+		 * so parents of a hotplug port must stay awake. In addition,
+		 * hotplug ports handled by firmware in System Management Mode
+		 * may not be put into D3 by the OS (Thunderbolt on non-Macs).
+		 * For simplicity, disallow in general for now.
+		 */
+		if (bridge->is_hotplug_bridge)
+			return false;
+
 		if (pci_bridge_d3_force)
 			return true;