ENGR00278492 imx: pcie: delay is required after REF_CLK_EN is set

delay is required after REF_CLK_EN of GPR1 is set.
otherwise, system would be hang when access the registers
of PCIe RC when the EARLY_PRINTK is not enabled.

Signed-off-by: Richard Zhu <r65037@freescale.com>

diff --git a/drivers/pci/host/pcie-imx.c b/drivers/pci/host/pcie-imx.c
index 192b2f4ac0b08a6d2be9ea21f3acb6d2acc3e00b..22af44af46d8e6b9e3131a553e5fd9714f2a2ca9 100644 (file)
--- a/drivers/pci/host/pcie-imx.c
+++ b/drivers/pci/host/pcie-imx.c
@@ -468,6 +468,7 @@ static int __init imx_pcie_probe(struct platform_device *pdev)
 
        regmap_update_bits(imx_pcie->gpr, IOMUXC_GPR1,
                        IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
+       usleep_range(1000, 2000);
 
        /* PCIE RESET, togle the external card's reset */
        imx_pcie->rst_gpio = of_get_named_gpio(np, "rst-gpios", 0);