[U-Boot] [PATCH 2/7] usb: hub: Conditionally power on usb's root-hub ports

[Vivek Gautam]

Power on root hubs' ports only when they are not yet powered on.
Its seen with USB 3.0 ports that they are powered on after
a H/W reset, as also reflected in XHCI spec (sec 4.3):
"After a Chip Hardware Reset, HCRST, or commanded to the
PLS = RxDetect state, all Root Hub ports shall be in Disconnected
state, i.e. the port is powered on (PP = 1)"

Signed-off-by: Amar <amarendra.xt at samsung.com>
Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
---
 common/usb_hub.c |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/common/usb_hub.c b/common/usb_hub.c
index b5eeb62..0677004 100644
--- a/common/usb_hub.c
+++ b/common/usb_hub.c
@@ -111,13 +111,29 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
 	int i;
 	struct usb_device *dev;
 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
+	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
+	unsigned short portstatus;
+	int ret;
 
 	dev = hub->pusb_dev;
-	/* Enable power to the ports */
+
+	/* Enable power to ports whose power is not yet on */
 	USB_HUB_PRINTF("enabling power on all ports\n");
 	for (i = 0; i < dev->maxchild; i++) {
-		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
-		USB_HUB_PRINTF("port %d returns %lX\n", i + 1, dev->status);
+		ret = usb_get_port_status(dev, i + 1, portsts);
+		if (ret < 0) {
+			USB_HUB_PRINTF("port %d: get_port_status failed\n",
+					i + 1);
+			return;
+		}
+
+		portstatus = le16_to_cpu(portsts->wPortStatus);
+
+		if (!(portstatus & (USB_PORT_STAT_POWER << 1))) {
+			usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
+			USB_HUB_PRINTF("port %d returns %lX\n", i + 1,
+					dev->status);
+		}
 	}
 
 	/* Wait at least 100 msec for power to become stable */
-- 
1.7.6.5