If we're probing the PCI controller and some GPIOs are not available and
cause a probe defer, we can end up leaving some ports initialized and
not others and making a mess.
Check for PERST# GPIOs for all ports first, and just return
-EPROBE_DEFER if any are not ready yet, without bringing anything up.
Fixes: 1e33888fbe44 ("PCI: apple: Add initial hardware bring-up")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
drivers/pci/controller/pcie-apple.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index e0c06c0ee731..e3aa2d461739 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -507,6 +507,20 @@ static u32 apple_pcie_rid2sid_write(struct apple_pcie_port *port,
return readl_relaxed(port->base + PORT_RID2SID(idx));
}
+static int apple_pcie_probe_port(struct device_node *np)
+{
+ struct gpio_desc *gd;
+
+ gd = gpiod_get_from_of_node(np, "reset-gpios", 0,
+ GPIOD_OUT_LOW, "PERST#");
+ if (IS_ERR(gd)) {
+ return PTR_ERR(gd);
+ }
+
+ gpiod_put(gd);
+ return 0;
+}
+
static int apple_pcie_setup_port(struct apple_pcie *pcie,
struct device_node *np)
{
@@ -797,8 +811,18 @@ static int apple_pcie_init(struct pci_config_window *cfg)
static int apple_pcie_probe(struct platform_device *pdev)
{
+ struct device *dev = &pdev->dev;
+ struct device_node *of_port;
int ret;
+ /* Check for probe dependencies for all ports first */
+ for_each_child_of_node(dev->of_node, of_port) {
+ ret = apple_pcie_probe_port(of_port);
+ of_node_put(of_port);
+ if (ret)
+ return dev_err_probe(dev, ret, "Port %pOF probe fail\n", of_port);
+ }
+
ret = bus_register_notifier(&pci_bus_type, &apple_pcie_nb);
if (ret)
return ret;
--
2.35.1
