From 7bf9d2af7e89f65a79225e26d261b52ce4ee3e95 Mon Sep 17 00:00:00 2001 From: Vidya Sagar Date: Tue, 16 Jan 2024 20:02:58 +0530 Subject: [PATCH] PCI: Clear Secondary Status errors after enumeration We enumerate devices by attempting config reads to the Vendor ID of each possible device. On conventional PCI, if no device responds, the read terminates with a Master Abort (PCI r3.0, sec 6.1). On PCIe, the config read is terminated as an Unsupported Request (PCIe r6.0, sec 2.3.2, 7.5.1.3.7). In either case, if the read addressed a device below a bridge, it is logged by setting "Received Master Abort" in the bridge Secondary Status register. Clear any errors logged in the Secondary Status register after enumeration. Link: https://lore.kernel.org/r/20240116143258.483235-1-vidyas@nvidia.com Signed-off-by: Vidya Sagar [bhelgaas: simplify commit log] Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 1325fbae2f28..df5171b912e0 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1482,6 +1482,9 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, } out: + /* Clear errors in the Secondary Status Register */ + pci_write_config_word(dev, PCI_SEC_STATUS, 0xffff); + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); pm_runtime_put(&dev->dev);