1 files changed, 40 insertions, 11 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f6c6b6f7cc9..5da5394127e 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -141,19 +141,27 @@ static int usb_device_supports_lpm(struct usb_device *udev)
 		return 0;
 	}
 
-	/* All USB 3.0 must support LPM, but we need their max exit latency
-	 * information from the SuperSpeed Extended Capabilities BOS descriptor.
+	/*
+	 * According to the USB 3.0 spec, all USB 3.0 devices must support LPM.
+	 * However, there are some that don't, and they set the U1/U2 exit
+	 * latencies to zero.
 	 */
 	if (!udev->bos->ss_cap) {
-		dev_warn(&udev->dev, "No LPM exit latency info found.  "
-				"Power management will be impacted.\n");
+		dev_info(&udev->dev, "No LPM exit latency info found, disabling LPM.\n");
+		return 0;
+	}
+
+	if (udev->bos->ss_cap->bU1devExitLat == 0 &&
+			udev->bos->ss_cap->bU2DevExitLat == 0) {
+		if (udev->parent)
+			dev_info(&udev->dev, "LPM exit latency is zeroed, disabling LPM.\n");
+		else
+			dev_info(&udev->dev, "We don't know the algorithms for LPM for this host, disabling LPM.\n");
 		return 0;
 	}
-	if (udev->parent->lpm_capable)
-		return 1;
 
-	dev_warn(&udev->dev, "Parent hub missing LPM exit latency info.  "
-			"Power management will be impacted.\n");
+	if (!udev->parent || udev->parent->lpm_capable)
+		return 1;
 	return 0;
 }
 
@@ -4750,6 +4758,8 @@ static void hub_events(void)
 
 		/* deal with port status changes */
 		for (i = 1; i <= hdev->maxchild; i++) {
+			struct usb_device *udev = hub->ports[i - 1]->child;
+
 			if (test_bit(i, hub->busy_bits))
 				continue;
 			connect_change = test_bit(i, hub->change_bits);
@@ -4848,8 +4858,6 @@ static void hub_events(void)
 			 */
 			if (hub_port_warm_reset_required(hub, portstatus)) {
 				int status;
-				struct usb_device *udev =
-					hub->ports[i - 1]->child;
 
 				dev_dbg(hub_dev, "warm reset port %d\n", i);
 				if (!udev ||
@@ -4866,6 +4874,24 @@ static void hub_events(void)
 					usb_unlock_device(udev);
 					connect_change = 0;
 				}
+			/*
+			 * On disconnect USB3 protocol ports transit from U0 to
+			 * SS.Inactive to Rx.Detect. If this happens a warm-
+			 * reset is not needed, but a (re)connect may happen
+			 * before khubd runs and sees the disconnect, and the
+			 * device may be an unknown state.
+			 *
+			 * If the port went through SS.Inactive without khubd
+			 * seeing it the C_LINK_STATE change flag will be set,
+			 * and we reset the dev to put it in a known state.
+			 */
+			} else if (udev && hub_is_superspeed(hub->hdev) &&
+				   (portchange & USB_PORT_STAT_C_LINK_STATE) &&
+				   (portstatus & USB_PORT_STAT_CONNECTION)) {
+				usb_lock_device(udev);
+				usb_reset_device(udev);
+				usb_unlock_device(udev);
+				connect_change = 0;
 			}
 
 			if (connect_change)
@@ -5123,7 +5149,7 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
 	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
 	struct usb_device_descriptor	descriptor = udev->descriptor;
 	struct usb_host_bos		*bos;
-	int 				i, ret = 0;
+	int				i, j, ret = 0;
 	int				port1 = udev->portnum;
 
 	if (udev->state == USB_STATE_NOTATTACHED ||
@@ -5249,6 +5275,9 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
 				ret);
 			goto re_enumerate;
 		}
+		/* Resetting also frees any allocated streams */
+		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++)
+			intf->cur_altsetting->endpoint[j].streams = 0;
 	}
 
 done: