From: Bjorn Helgaas <>

Previously "pcie_port_pm=force" enabled power management of PCI bridges,
but only for PCIe ports (not conventional PCI bridges) and only for ports
that do not support hotplug.  Those limitations are there because we're not
confident that all those configurations work, not because the spec requires

Change "pcie_port_pm=force" to enable power management of conventional PCI
bridges and hotplug bridges as well as PCIe ports.  As with the previous
PCIe port-only behavior, this is not expected to work in all systems.

Add a "pci=bridge_pm" parameter to reflect the increased scope.  For
backward compatibility, retain "pcie_port_pm=force" as an undocumented

Add "pci=no_bridge_pm" as an equivalent to "pcie_port_pm=off".  This
disables power management for all PCI bridges, which is results in the same
behavior as before, since we always disabled power management of
conventional PCI bridges, and "pcie_port_pm=off" disabled it for PCIe

Signed-off-by: Bjorn Helgaas <>
 Documentation/admin-guide/kernel-parameters.txt |    8 ++++----
 drivers/pci/pci.c                               |   21 ++++++++++++---------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt 
index 1d1d53f85ddd..4660105ec851 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3117,6 +3117,10 @@
                pcie_scan_all   Scan all possible PCIe devices.  Otherwise we
                                only look for one device below a PCIe downstream
+               bridge_pm       Enable runtime power management of all bridges,
+                               including conventional PCI bridges, PCIe ports,
+                               and hotplug bridges.
+               no_bridge_pm    Disable runtime power management of all bridges.
                big_root_window Try to add a big 64bit memory window to the PCIe
                                root complex on AMD CPUs. Some GFX hardware
                                can resize a BAR to allow access to all VRAM.
@@ -3143,10 +3147,6 @@
                compat  Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe
                        ports driver.
-       pcie_port_pm=   [PCIE] PCIe port power management handling:
-               off     Disable power management of all PCIe ports
-               force   Forcibly enable power management of all PCIe ports
        pcie_pme=       [PCIE,PM] Native PCIe PME signaling options:
                nomsi   Do not use MSI for native PCIe PME signaling (this makes
                        all PCIe root ports use INTx for all services).
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 75db77cf3f8f..2aa1ae9c4afa 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -111,10 +111,8 @@ unsigned int pcibios_max_latency = 255;
 /* If set, the PCIe ARI capability will not be used. */
 static bool pcie_ari_disabled;
-/* Disable bridge_d3 for all PCIe ports */
-static bool pci_bridge_d3_disable;
-/* Force bridge_d3 for all PCIe ports */
-static bool pci_bridge_d3_force;
+static bool pci_bridge_d3_disable;     /* Disable D3 for all bridges */
+static bool pci_bridge_d3_force;       /* Enable D3 for all bridges */
 static int __init pcie_port_pm_setup(char *str)
@@ -2260,6 +2258,12 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
        unsigned int year;
+       if (pci_bridge_d3_disable)
+               return false;
+       if (pci_bridge_d3_force)
+               return true;
         * In principle we should be able to put conventional PCI bridges
         * into D3.  We only support it for PCIe because (a) we want to
@@ -2274,8 +2278,6 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
        case PCI_EXP_TYPE_ROOT_PORT:
-               if (pci_bridge_d3_disable)
-                       return false;
                 * Hotplug interrupts cannot be delivered if the link is down,
@@ -2295,9 +2297,6 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
                if (bridge->is_hotplug_bridge)
                        return false;
-               if (pci_bridge_d3_force)
-                       return true;
                 * It should be safe to put PCIe ports from 2015 or newer
                 * to D3.  We have vague reports of possible hardware
@@ -5708,6 +5707,10 @@ static int __init pci_setup(char *str)
                                pcie_bus_config = PCIE_BUS_PEER2PEER;
                        } else if (!strncmp(str, "pcie_scan_all", 13)) {
+                       } else if (!strncmp(str, "bridge_pm", 9)) {
+                               pci_bridge_d3_force = true;
+                       } else if (!strncmp(str, "no_bridge_pm", 12)) {
+                               pci_bridge_d3_disable = true;
                        } else {
                                printk(KERN_ERR "PCI: Unknown option `%s'\n",

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