1 files changed, 52 insertions, 16 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index ddbf32d599cb..51b436918f78 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3324,7 +3324,7 @@ static int finish_port_resume(struct usb_device *udev)
 /*
  * There are some SS USB devices which take longer time for link training.
  * XHCI specs 4.19.4 says that when Link training is successful, port
- * sets CSC bit to 1. So if SW reads port status before successful link
+ * sets CCS bit to 1. So if SW reads port status before successful link
  * training, then it will not find device to be present.
  * USB Analyzer log with such buggy devices show that in some cases
  * device switch on the RX termination after long delay of host enabling
@@ -3335,14 +3335,17 @@ static int finish_port_resume(struct usb_device *udev)
  * routine implements a 2000 ms timeout for link training. If in a case
  * link trains before timeout, loop will exit earlier.
  *
+ * There are also some 2.0 hard drive based devices and 3.0 thumb
+ * drives that, when plugged into a 2.0 only port, take a long
+ * time to set CCS after VBUS enable.
+ *
  * FIXME: If a device was connected before suspend, but was removed
  * while system was asleep, then the loop in the following routine will
  * only exit at timeout.
  *
- * This routine should only be called when persist is enabled for a SS
- * device.
+ * This routine should only be called when persist is enabled.
  */
-static int wait_for_ss_port_enable(struct usb_device *udev,
+static int wait_for_connected(struct usb_device *udev,
 		struct usb_hub *hub, int *port1,
 		u16 *portchange, u16 *portstatus)
 {
@@ -3355,6 +3358,7 @@ static int wait_for_ss_port_enable(struct usb_device *udev,
 		delay_ms += 20;
 		status = hub_port_status(hub, *port1, portstatus, portchange);
 	}
+	dev_dbg(&udev->dev, "Waited %dms for CONNECT\n", delay_ms);
 	return status;
 }
 
@@ -3454,8 +3458,8 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 		}
 	}
 
-	if (udev->persist_enabled && hub_is_superspeed(hub->hdev))
-		status = wait_for_ss_port_enable(udev, hub, &port1, &portchange,
+	if (udev->persist_enabled)
+		status = wait_for_connected(udev, hub, &port1, &portchange,
 				&portstatus);
 
 	status = check_port_resume_type(udev,
@@ -3895,17 +3899,30 @@ static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
 		return;
 	}
 
-	if (usb_set_lpm_timeout(udev, state, timeout))
+	if (usb_set_lpm_timeout(udev, state, timeout)) {
 		/* If we can't set the parent hub U1/U2 timeout,
 		 * device-initiated LPM won't be allowed either, so let the xHCI
 		 * host know that this link state won't be enabled.
 		 */
 		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
+	} else {
+		/* Only a configured device will accept the Set Feature
+		 * U1/U2_ENABLE
+		 */
+		if (udev->actconfig)
+			usb_set_device_initiated_lpm(udev, state, true);
 
-	/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
-	else if (udev->actconfig)
-		usb_set_device_initiated_lpm(udev, state, true);
-
+		/* As soon as usb_set_lpm_timeout(timeout) returns 0, the
+		 * hub-initiated LPM is enabled. Thus, LPM is enabled no
+		 * matter the result of usb_set_device_initiated_lpm().
+		 * The only difference is whether device is able to initiate
+		 * LPM.
+		 */
+		if (state == USB3_LPM_U1)
+			udev->usb3_lpm_u1_enabled = 1;
+		else if (state == USB3_LPM_U2)
+			udev->usb3_lpm_u2_enabled = 1;
+	}
 }
 
 /*
@@ -3945,6 +3962,18 @@ static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
 		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
 				"bus schedule bandwidth may be impacted.\n",
 				usb3_lpm_names[state]);
+
+	/* As soon as usb_set_lpm_timeout(0) return 0, hub initiated LPM
+	 * is disabled. Hub will disallows link to enter U1/U2 as well,
+	 * even device is initiating LPM. Hence LPM is disabled if hub LPM
+	 * timeout set to 0, no matter device-initiated LPM is disabled or
+	 * not.
+	 */
+	if (state == USB3_LPM_U1)
+		udev->usb3_lpm_u1_enabled = 0;
+	else if (state == USB3_LPM_U2)
+		udev->usb3_lpm_u2_enabled = 0;
+
 	return 0;
 }
 
@@ -3979,8 +4008,6 @@ int usb_disable_lpm(struct usb_device *udev)
 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
 		goto enable_lpm;
 
-	udev->usb3_lpm_enabled = 0;
-
 	return 0;
 
 enable_lpm:
@@ -4017,6 +4044,8 @@ EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
 void usb_enable_lpm(struct usb_device *udev)
 {
 	struct usb_hcd *hcd;
+	struct usb_hub *hub;
+	struct usb_port *port_dev;
 
 	if (!udev || !udev->parent ||
 			udev->speed != USB_SPEED_SUPER ||
@@ -4036,10 +4065,17 @@ void usb_enable_lpm(struct usb_device *udev)
 	if (udev->lpm_disable_count > 0)
 		return;
 
-	usb_enable_link_state(hcd, udev, USB3_LPM_U1);
-	usb_enable_link_state(hcd, udev, USB3_LPM_U2);
+	hub = usb_hub_to_struct_hub(udev->parent);
+	if (!hub)
+		return;
+
+	port_dev = hub->ports[udev->portnum - 1];
+
+	if (port_dev->usb3_lpm_u1_permit)
+		usb_enable_link_state(hcd, udev, USB3_LPM_U1);
 
-	udev->usb3_lpm_enabled = 1;
+	if (port_dev->usb3_lpm_u2_permit)
+		usb_enable_link_state(hcd, udev, USB3_LPM_U2);
 }
 EXPORT_SYMBOL_GPL(usb_enable_lpm);