>From DWC_usb31 databook section 1.3.2, once DWC3_DCTL_CSFTRST bit is cleared, we must wait at least 50ms before accessing the PHY domain (synchronization delay). Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx> --- drivers/usb/dwc3/core.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 07832509584f..7d21f21707f5 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -228,12 +228,23 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc) do { reg = dwc3_readl(dwc->regs, DWC3_DCTL); if (!(reg & DWC3_DCTL_CSFTRST)) - return 0; + goto done; udelay(1); } while (--retries); return -ETIMEDOUT; + +done: + /* + * For DWC_usb31 controller, once DWC3_DCTL_CSFTRST bit is cleared, + * we must wait at least 50ms before accessing the PHY domain + * (synchronization delay). DWC_usb31 Databook section 1.3.2. + */ + if (dwc3_is_usb31(dwc)) + mdelay(50); + + return 0; } /* -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html