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path: root/drivers/pci/host/pci-imx6.c
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Diffstat (limited to 'drivers/pci/host/pci-imx6.c')
-rw-r--r--drivers/pci/host/pci-imx6.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 233fe8a88264..69202d1eb8fb 100644
--- 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);
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