PCIe Spec 3.0. 7.10.2. Uncorrectable Error Status Register (Offset 04h) defines link down errors as an AER error as bit 5 Surprise Down Error Status.
If hotplug is supported by a particular port, we want hotplug driver to handle the link down/up conditions via Data Link Layer Active interrupt rather than the AER error interrupt. Mask the Surprise Down Error during hotplug driver and re-enable it during remove. Signed-off-by: Sinan Kaya <[email protected]> --- drivers/pci/hotplug/pciehp_core.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index ec48c9433ae5..8322db8f369a 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -229,6 +229,29 @@ static void pciehp_check_presence(struct controller *ctrl) up_read(&ctrl->reset_lock); } +static int pciehp_control_surprise_error(struct controller *ctrl, bool enable) +{ + struct pci_dev *pdev = ctrl->pcie->port; + u32 reg32; + int pos; + + if (!pci_is_pcie(pdev)) + return -ENODEV; + + pos = pdev->aer_cap; + if (!pos) + return -ENODEV; + + pci_read_config_dword(pdev, pos + PCI_ERR_UNCOR_MASK, ®32); + if (enable) + reg32 &= ~PCI_ERR_UNC_SURPDN; + else + reg32 |= PCI_ERR_UNC_SURPDN; + pci_write_config_dword(pdev, pos + PCI_ERR_UNCOR_MASK, reg32); + + return 0; +} + static int pciehp_probe(struct pcie_device *dev) { int rc; @@ -280,6 +303,9 @@ static int pciehp_probe(struct pcie_device *dev) pciehp_check_presence(ctrl); + /* We want exclusive control of link down events in hotplug driver */ + pciehp_control_surprise_error(ctrl, false); + return 0; err_out_shutdown_notification: @@ -298,6 +324,7 @@ static void pciehp_remove(struct pcie_device *dev) pci_hp_del(ctrl->slot->hotplug_slot); pcie_shutdown_notification(ctrl); cleanup_slot(ctrl); + pciehp_control_surprise_error(ctrl, true); pciehp_release_ctrl(ctrl); } -- 2.17.1
