From: Bjorn Helgaas bhelgaas@google.com
[ Upstream commit 3f8c4959fc18e477801386a625e726c59f52a2c4 ]
Following a reset, a Function may respond to Config Requests with Request Retry Status (RRS) Completion Status to indicate that it is temporarily unable to process the Request, but will be able to process the Request in the future (PCIe r6.0, sec 2.3.1).
If the Configuration RRS Software Visibility feature is enabled and a Root Complex receives RRS for a config read of the Vendor ID, the Root Complex completes the Request to the host by returning PCI_VENDOR_ID_PCI_SIG, 0x0001 (sec 2.3.2).
The Config RRS SV feature applies only to Root Ports and is not directly related to pci_scan_bridge_extend(). Move the RRS SV enable to set_pcie_port_type() where we handle other PCIe-specific configuration.
Link: https://lore.kernel.org/r/20250303210217.199504-1-helgaas@kernel.org Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/probe.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index ebb0c1d5cae25..a4330ad7cdfdf 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1328,8 +1328,6 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
- pci_enable_rrs_sv(dev); - if ((secondary || subordinate) && !pcibios_assign_all_busses() && !is_cardbus && !broken) { unsigned int cmax, buses; @@ -1570,6 +1568,11 @@ void set_pcie_port_type(struct pci_dev *pdev) pdev->pcie_cap = pos; pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, ®16); pdev->pcie_flags_reg = reg16; + + type = pci_pcie_type(pdev); + if (type == PCI_EXP_TYPE_ROOT_PORT) + pci_enable_rrs_sv(pdev); + pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap); pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);
@@ -1586,7 +1589,6 @@ void set_pcie_port_type(struct pci_dev *pdev) * correctly so detect impossible configurations here and correct * the port type accordingly. */ - type = pci_pcie_type(pdev); if (type == PCI_EXP_TYPE_DOWNSTREAM) { /* * If pdev claims to be downstream port but the parent