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@vger.kernel.org Signed-off-by: Hector Martin marcan@marcan.st --- 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;