[PATCH v2] PCI: host-common: Request bus reassignment when not probe-only

[Ratheesh Kannoth]

pci_host_common_init() is used by several generic ECAM host drivers.
After PCI core changes around pci_flags and preserve_config, these hosts
no longer opted into full bus number reassignment the way they did
before.

When PCI_PROBE_ONLY is not set, add PCI_REASSIGN_ALL_BUS so
pci_scan_bridge_extend() takes the reassignment path: bus numbers can be
assigned from firmware EA data (e.g. pci_ea_fixed_busnrs()). Skip the
flag in probe-only mode so existing assignments are not overridden.

CC: Bjorn Helgaas <helgaas@xxxxxxxxxx>
CC: Vidya Sagar <vidyas@xxxxxxxxxx>
CC: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Fixes: 7246a4520b4b ("PCI: Use preserve_config in place of pci_flags")
Link: https://lore.kernel.org/netdev/adcXzcz2wWJFw4d7@rkannoth-OptiPlex-7090/
Signed-off-by: Ratheesh Kannoth <rkannoth@xxxxxxxxxxx>

---
v1 -> v2 : https://lore.kernel.org/linux-pci/20260410142124.2673056-1-rkannoth@xxxxxxxxxxx/
---
 drivers/pci/controller/pci-host-common.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index d6258c1cffe5..99952fb7189b 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -68,6 +68,10 @@ int pci_host_common_init(struct platform_device *pdev,
 	if (IS_ERR(cfg))
 		return PTR_ERR(cfg);
 
+	/* Do not reassign bus numbers if probe only */
+	if (!pci_has_flag(PCI_PROBE_ONLY))
+		pci_add_flags(PCI_REASSIGN_ALL_BUS);
+
 	bridge->sysdata = cfg;
 	bridge->ops = (struct pci_ops *)&ops->pci_ops;
 	bridge->enable_device = ops->enable_device;
-- 
2.43.0