PLX switches have an issue that their internal registers become inaccessible when runtime PM is enabled. Therefore PLX service tools can't communicate with the hardware. A kernel option "pcie_port_pm=off" can be used as a workaround. But it affects all the devices. So this solution is to add PLX switch devices to the quirk list for disabling runtime PM only for them. --- drivers/pci/quirks.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index a59ad09..8ea99aa 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -2923,6 +2923,17 @@ static void quirk_hotplug_bridge(struct pci_dev *dev) dev->is_hotplug_bridge = 1; } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_HINT, 0x0020, quirk_hotplug_bridge); +/* + * Disable runtime PM for PLX Draco (1,2), Capella (1,2) series PCIe switches + * to prevent service tools from failing to access hardware registers. + */ +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x8712, quirk_hotplug_bridge); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x8733, quirk_hotplug_bridge); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x8734, quirk_hotplug_bridge); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x8780, quirk_hotplug_bridge); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x8796, quirk_hotplug_bridge); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x9781, quirk_hotplug_bridge); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x9797, quirk_hotplug_bridge); /* * This is a quirk for the Ricoh MMC controller found as a part of some -- 2.7.4
