From: Sebastian Hesselbarth <sebastian.hesselba...@gmail.com>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit b42285f66f871a9898a0e79e2d74bc7e7a101995 upstream.

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.hesselba...@gmail.com>
Signed-off-by: Jason Cooper <ja...@lakedaemon.net>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
---
 drivers/pci/host/pci-mvebu.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 1953c1680986..8efd11dafd44 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -866,11 +866,23 @@ 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;
                }
 
@@ -886,22 +898,9 @@ 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++;
        }
 
-- 
1.9.2

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