[U-Boot] [PATCH 1/2] usb: xhci: dwc3: Adding reset delay requirement as per dwc3 databook

Rajesh Bhagat rajesh.bhagat at freescale.com
Wed Dec 2 07:14:27 CET 2015


As per dwc3 databook, delay is required before taking the core out of reset.
This delay is required so that the PHY are stable, and then we can take core
out of reset.

Reference is taken from linux dwc3 code, file: drivers/usb/dwc3/core.c.

Signed-off-by: Sriram Dash <sriram.dash at freescale.com>
Signed-off-by: Rajesh Bhagat <rajesh.bhagat at freescale.com>
---
 drivers/usb/host/xhci-dwc3.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/xhci-dwc3.c b/drivers/usb/host/xhci-dwc3.c
index c722c50..33961cd 100644
--- a/drivers/usb/host/xhci-dwc3.c
+++ b/drivers/usb/host/xhci-dwc3.c
@@ -44,6 +44,8 @@ void dwc3_core_soft_reset(struct dwc3 *dwc3_reg)
 	/* reset USB3 phy - if required */
 	dwc3_phy_reset(dwc3_reg);
 
+	mdelay(100);
+
 	/* After PHYs are stable we can take Core out of reset state */
 	clrbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);
 }
-- 
2.6.2.198.g614a2ac



More information about the U-Boot mailing list