2 files changed, 90 insertions, 4 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 2a369d3fc3a..0e330a1de06 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -644,6 +644,60 @@ static int hub_hub_status(struct usb_hub *hub,
 	return ret;
 }
 
+static int hub_set_port_link_state(struct usb_hub *hub, int port1,
+			unsigned int link_status)
+{
+	return set_port_feature(hub->hdev,
+			port1 | (link_status << 3),
+			USB_PORT_FEAT_LINK_STATE);
+}
+
+/*
+ * If USB 3.0 ports are placed into the Disabled state, they will no longer
+ * detect any device connects or disconnects.  This is generally not what the
+ * USB core wants, since it expects a disabled port to produce a port status
+ * change event when a new device connects.
+ *
+ * Instead, set the link state to Disabled, wait for the link to settle into
+ * that state, clear any change bits, and then put the port into the RxDetect
+ * state.
+ */
+static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
+{
+	int ret;
+	int total_time;
+	u16 portchange, portstatus;
+
+	if (!hub_is_superspeed(hub->hdev))
+		return -EINVAL;
+
+	ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
+	if (ret) {
+		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
+				port1, ret);
+		return ret;
+	}
+
+	/* Wait for the link to enter the disabled state. */
+	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
+		ret = hub_port_status(hub, port1, &portstatus, &portchange);
+		if (ret < 0)
+			return ret;
+
+		if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
+				USB_SS_PORT_LS_SS_DISABLED)
+			break;
+		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
+			break;
+		msleep(HUB_DEBOUNCE_STEP);
+	}
+	if (total_time >= HUB_DEBOUNCE_TIMEOUT)
+		dev_warn(hub->intfdev, "Could not disable port %d after %d ms\n",
+				port1, total_time);
+
+	return hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_RX_DETECT);
+}
+
 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
 {
 	struct usb_device *hdev = hub->hdev;
@@ -652,8 +706,13 @@ static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
 	if (hdev->children[port1-1] && set_state)
 		usb_set_device_state(hdev->children[port1-1],
 				USB_STATE_NOTATTACHED);
-	if (!hub->error && !hub_is_superspeed(hub->hdev))
-		ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
+	if (!hub->error) {
+		if (hub_is_superspeed(hub->hdev))
+			ret = hub_usb3_port_disable(hub, port1);
+		else
+			ret = clear_port_feature(hdev, port1,
+					USB_PORT_FEAT_ENABLE);
+	}
 	if (ret)
 		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
 				port1, ret);
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index de07b7556d4..0efc857ed1e 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -753,12 +753,39 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			break;
 		case USB_PORT_FEAT_LINK_STATE:
 			temp = xhci_readl(xhci, port_array[wIndex]);
+
+			/* Disable port */
+			if (link_state == USB_SS_PORT_LS_SS_DISABLED) {
+				xhci_dbg(xhci, "Disable port %d\n", wIndex);
+				temp = xhci_port_state_to_neutral(temp);
+				/*
+				 * Clear all change bits, so that we get a new
+				 * connection event.
+				 */
+				temp |= PORT_CSC | PORT_PEC | PORT_WRC |
+					PORT_OCC | PORT_RC | PORT_PLC |
+					PORT_CEC;
+				xhci_writel(xhci, temp | PORT_PE,
+					port_array[wIndex]);
+				temp = xhci_readl(xhci, port_array[wIndex]);
+				break;
+			}
+
+			/* Put link in RxDetect (enable port) */
+			if (link_state == USB_SS_PORT_LS_RX_DETECT) {
+				xhci_dbg(xhci, "Enable port %d\n", wIndex);
+				xhci_set_link_state(xhci, port_array, wIndex,
+						link_state);
+				temp = xhci_readl(xhci, port_array[wIndex]);
+				break;
+			}
+
 			/* Software should not attempt to set
-			 * port link state above '5' (Rx.Detect) and the port
+			 * port link state above '3' (U3) and the port
 			 * must be enabled.
 			 */
 			if ((temp & PORT_PE) == 0 ||
-				(link_state > USB_SS_PORT_LS_RX_DETECT)) {
+				(link_state > USB_SS_PORT_LS_U3)) {
 				xhci_warn(xhci, "Cannot set link state.\n");
 				goto error;
 			}