Hi Richard, On Fri, Oct 24, 2014 at 12:30 AM, Richard Zhu <richard.zhu@xxxxxxxxxxxxx> wrote: > - /* 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); I am curious about this delay here: have you seen boot issues without it? If so, which hardware was that? -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html