Commit ee1604381a371 ("PCI: mvebu: Only remap I/O space if
configured") had the side effect that the PCI I/O mapping was created
much earlier than before, at a point where the probe() of the driver
could still fail. This is for example a problem if one gets an
-EPROBE_DEFER at some point during probe(), after pci_ioremap_io() has
been called.
Indeed, there is currently no function to undo what pci_ioremap_io()
did, and switching to pci_remap_iospace() is not an option in
pci-mvebu due to the need for special memory attributes on Armada 38x.
Reverting ee1604381a371 ("PCI: mvebu: Only remap I/O space if
configured") would be a possibility, but it would require also
reverting 42342073e38b5 ("PCI: mvebu: Convert to use pci_host_bridge
directly"). So instead, we use an open-coded version of
pci_host_probe() that creates the PCI I/O mapping at a point where we
are guaranteed not to fail anymore.
Reported-by: Jan Kundrát <jan.kundrat@xxxxxxxxx>
Fixes: ee1604381a371 ("PCI: mvebu: Only remap I/O space if configured")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx>
---
drivers/pci/controller/pci-mvebu.c | 52 +++++++++++++++++++++++++++++++++++---
1 file changed, 48 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index 50eb0729385b..a41d79b8d46a 100644
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -1145,7 +1145,6 @@ static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
{
struct device *dev = &pcie->pdev->dev;
struct device_node *np = dev->of_node;
- unsigned int i;
int ret;
INIT_LIST_HEAD(&pcie->resources);
@@ -1179,13 +1178,58 @@ static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
resource_size(&pcie->io) - 1);
pcie->realio.name = "PCI I/O";
+ pci_add_resource(&pcie->resources, &pcie->realio);
+ }
+
+ return devm_request_pci_bus_resources(dev, &pcie->resources);
+}
+
+/*
+ * This is a copy of pci_host_probe(), except that it does the I/O
+ * remap as the last step, once we are sure we won't fail.
+ *
+ * It should be removed once the I/O remap error handling issue has
+ * been sorted out.
+ */
+static int mvebu_pci_host_probe(struct pci_host_bridge *bridge)
+{
+ struct mvebu_pcie *pcie;
+ struct pci_bus *bus, *child;
+ int ret;
+
+ ret = pci_scan_root_bus_bridge(bridge);
+ if (ret < 0) {
+ dev_err(bridge->dev.parent, "Scanning root bridge failed");
+ return ret;
+ }
+
+ pcie = pci_host_bridge_priv(bridge);
+ if (resource_size(&pcie->io) != 0) {
+ unsigned int i;
+
for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)
pci_ioremap_io(i, pcie->io.start + i);
+ }
- pci_add_resource(&pcie->resources, &pcie->realio);
+ bus = bridge->bus;
+
+ /*
+ * We insert PCI resources into the iomem_resource and
+ * ioport_resource trees in either pci_bus_claim_resources()
+ * or pci_bus_assign_resources().
+ */
+ if (pci_has_flag(PCI_PROBE_ONLY)) {
+ pci_bus_claim_resources(bus);
+ } else {
+ pci_bus_size_bridges(bus);
+ pci_bus_assign_resources(bus);
+
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
}
- return devm_request_pci_bus_resources(dev, &pcie->resources);
+ pci_bus_add_devices(bus);
+ return 0;
}
static int mvebu_pcie_probe(struct platform_device *pdev)
@@ -1268,7 +1312,7 @@ static int mvebu_pcie_probe(struct platform_device *pdev)
bridge->align_resource = mvebu_pcie_align_resource;
bridge->msi = pcie->msi;
- return pci_host_probe(bridge);
+ return mvebu_pci_host_probe(bridge);
}
static const struct of_device_id mvebu_pcie_of_match_table[] = {
--
2.14.4
