From: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Date: Tue, 13 Aug 2013 12:25:20 +0000 (+0200)
Subject: PCI: mvebu: move clock enable before register access
X-Git-Tag: next-20130822~13^2^2~12
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=826727641b2a137d95efab0f579160ae5864f780;p=karo-tx-linux.git

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 46cef5c594de..657bd8933686 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -922,10 +922,22 @@ 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 (!port->base) {
 			dev_err(&pdev->dev, "PCIe%d.%d: cannot map registers\n",
 				port->port, port->lane);
+			clk_disable_unprepare(port->clk);
 			continue;
 		}
 
@@ -941,22 +953,9 @@ 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++;
 	}