Merge tag 'pci-v3.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaa...

[pandora-kernel.git] / drivers / pci / host / pci-imx6.c

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 8a7530b..d1a26d1 100644 (file)
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -275,15 +275,22 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
                goto err_pcie;
        }
 
-       /* allow the clocks to stabilize */
-       usleep_range(200, 500);
-
        /* power up core phy and enable ref clock */
        regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
                        IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
+       /*
+        * the async reset input need ref clock to sync internally,
+        * when the ref clock comes after reset, internal synced
+        * reset time is too short, cannot meet the requirement.
+        * add one ~10us delay here.
+        */
+       udelay(10);
        regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
                        IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
 
+       /* allow the clocks to stabilize */
+       usleep_range(200, 500);
+
        /* Some boards don't have PCIe reset GPIO. */
        if (gpio_is_valid(imx6_pcie->reset_gpio)) {
                gpio_set_value(imx6_pcie->reset_gpio, 0);