PCI: mvebu: move clock enable before register access

The clock passed to PCI controller found on MVEBU SoCs may come from a
clock gate. This requires the clock to be enabled before any registers
are accessed. Therefore, move the clock enable before register iomap to
ensure it is enabled.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 32ac56414465cfcd8521d30f78c343702990618d..5c327ce846dcfd82151585bebcb009bf23d47649 100644 (file)
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -897,11 +897,23 @@ static int __init mvebu_pcie_probe(struct platform_device *pdev)
                        continue;
                }
 
+               port->clk = of_clk_get_by_name(child, NULL);
+               if (IS_ERR(port->clk)) {
+                       dev_err(&pdev->dev, "PCIe%d.%d: cannot get clock\n",
+                              port->port, port->lane);
+                       continue;
+               }
+
+               ret = clk_prepare_enable(port->clk);
+               if (ret)
+                       continue;
+
                port->base = mvebu_pcie_map_registers(pdev, child, port);
                if (IS_ERR(port->base)) {
                        dev_err(&pdev->dev, "PCIe%d.%d: cannot map registers\n",
                                port->port, port->lane);
                        port->base = NULL;
+                       clk_disable_unprepare(port->clk);
                        continue;
                }
 
@@ -917,22 +929,9 @@ static int __init mvebu_pcie_probe(struct platform_device *pdev)
                                 port->port, port->lane);
                }
 
-               port->clk = of_clk_get_by_name(child, NULL);
-               if (IS_ERR(port->clk)) {
-                       dev_err(&pdev->dev, "PCIe%d.%d: cannot get clock\n",
-                              port->port, port->lane);
-                       iounmap(port->base);
-                       port->haslink = 0;
-                       continue;
-               }
-
                port->dn = child;
-
-               clk_prepare_enable(port->clk);
                spin_lock_init(&port->conf_lock);
-
                mvebu_sw_pci_bridge_init(port);
-
                i++;
        }