1 files changed, 78 insertions, 16 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 0e950ad..8a4dcbc 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2606,13 +2606,20 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 /* Is a USB 3.0 port in the Inactive or Compliance Mode state?
  * Port worm reset is required to recover
  */
-static bool hub_port_warm_reset_required(struct usb_hub *hub, u16 portstatus)
+static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
+		u16 portstatus)
 {
-	return hub_is_superspeed(hub->hdev) &&
-		(((portstatus & USB_PORT_STAT_LINK_STATE) ==
-		  USB_SS_PORT_LS_SS_INACTIVE) ||
-		 ((portstatus & USB_PORT_STAT_LINK_STATE) ==
-		  USB_SS_PORT_LS_COMP_MOD)) ;
+	u16 link_state;
+
+	if (!hub_is_superspeed(hub->hdev))
+		return false;
+
+	if (test_bit(port1, hub->warm_reset_bits))
+		return true;
+
+	link_state = portstatus & USB_PORT_STAT_LINK_STATE;
+	return link_state == USB_SS_PORT_LS_SS_INACTIVE
+		|| link_state == USB_SS_PORT_LS_COMP_MOD;
 }
 
 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
@@ -2649,7 +2656,7 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1,
 	if ((portstatus & USB_PORT_STAT_RESET))
 		return -EBUSY;
 
-	if (hub_port_warm_reset_required(hub, portstatus))
+	if (hub_port_warm_reset_required(hub, port1, portstatus))
 		return -ENOTCONN;
 
 	/* Device went away? */
@@ -2749,9 +2756,10 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 		if (status < 0)
 			goto done;
 
-		if (hub_port_warm_reset_required(hub, portstatus))
+		if (hub_port_warm_reset_required(hub, port1, portstatus))
 			warm = true;
 	}
+	clear_bit(port1, hub->warm_reset_bits);
 
 	/* Reset the port */
 	for (i = 0; i < PORT_RESET_TRIES; i++) {
@@ -2788,7 +2796,8 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 					&portstatus, &portchange) < 0)
 				goto done;
 
-			if (!hub_port_warm_reset_required(hub, portstatus))
+			if (!hub_port_warm_reset_required(hub, port1,
+					portstatus))
 				goto done;
 
 			/*
@@ -2875,8 +2884,13 @@ static int check_port_resume_type(struct usb_device *udev,
 {
 	struct usb_port *port_dev = hub->ports[port1 - 1];
 
+	/* Is a warm reset needed to recover the connection? */
+	if (status == 0 && udev->reset_resume
+		&& hub_port_warm_reset_required(hub, port1, portstatus)) {
+		/* pass */;
+	}
 	/* Is the device still present? */
-	if (status || port_is_suspended(hub, portstatus) ||
+	else if (status || port_is_suspended(hub, portstatus) ||
 			!port_is_power_on(hub, portstatus) ||
 			!(portstatus & USB_PORT_STAT_CONNECTION)) {
 		if (status >= 0)
@@ -3264,6 +3278,43 @@ 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
+ * 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
+ * the VBUS. In few other cases it has been seen that device fails to
+ * negotiate link training in first attempt. It has been
+ * reported till now that few devices take as long as 2000 ms to train
+ * the link after host enabling its VBUS and termination. Following
+ * routine implements a 2000 ms timeout for link training. If in a case
+ * link trains before timeout, loop will exit earlier.
+ *
+ * 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.
+ */
+static int wait_for_ss_port_enable(struct usb_device *udev,
+		struct usb_hub *hub, int *port1,
+		u16 *portchange, u16 *portstatus)
+{
+	int status = 0, delay_ms = 0;
+
+	while (delay_ms < 2000) {
+		if (status || *portstatus & USB_PORT_STAT_CONNECTION)
+			break;
+		msleep(20);
+		delay_ms += 20;
+		status = hub_port_status(hub, *port1, portstatus, portchange);
+	}
+	return status;
+}
+
+/*
  * usb_port_resume - re-activate a suspended usb device's upstream port
  * @udev: device to re-activate, not a root hub
  * Context: must be able to sleep; device not locked; pm locks held
@@ -3359,6 +3410,10 @@ 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,
+				&portstatus);
+
 	status = check_port_resume_type(udev,
 			hub, port1, status, portchange, portstatus);
 	if (status == 0)
@@ -3879,7 +3934,8 @@ int usb_disable_lpm(struct usb_device *udev)
 
 	if (!udev || !udev->parent ||
 			udev->speed != USB_SPEED_SUPER ||
-			!udev->lpm_capable)
+			!udev->lpm_capable ||
+			udev->state < USB_STATE_DEFAULT)
 		return 0;
 
 	hcd = bus_to_hcd(udev->bus);
@@ -3935,7 +3991,8 @@ void usb_enable_lpm(struct usb_device *udev)
 
 	if (!udev || !udev->parent ||
 			udev->speed != USB_SPEED_SUPER ||
-			!udev->lpm_capable)
+			!udev->lpm_capable ||
+			udev->state < USB_STATE_DEFAULT)
 		return;
 
 	udev->lpm_disable_count--;
@@ -4550,6 +4607,7 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
 	struct usb_port *port_dev = hub->ports[port1 - 1];
 	struct usb_device *udev = port_dev->child;
+	static int unreliable_port = -1;
 
 	/* Disconnect any existing devices under this port */
 	if (udev) {
@@ -4570,10 +4628,14 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
 				USB_PORT_STAT_C_ENABLE)) {
 		status = hub_port_debounce_be_stable(hub, port1);
 		if (status < 0) {
-			if (status != -ENODEV && printk_ratelimit())
-				dev_err(&port_dev->dev,
-						"connect-debounce failed\n");
+			if (status != -ENODEV &&
+				port1 != unreliable_port &&
+				printk_ratelimit())
+				dev_err(&udev->dev, "connect-debounce failed, port %d disabled\n",
+					port1);
+
 			portstatus &= ~USB_PORT_STAT_CONNECTION;
+			unreliable_port = port1;
 		} else {
 			portstatus = status;
 		}
@@ -4889,7 +4951,7 @@ static void port_event(struct usb_hub *hub, int port1)
 	 * Warm reset a USB3 protocol port if it's in
 	 * SS.Inactive state.
 	 */
-	if (hub_port_warm_reset_required(hub, portstatus)) {
+	if (hub_port_warm_reset_required(hub, port1, portstatus)) {
 		dev_dbg(&port_dev->dev, "do warm reset\n");
 		if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
 				|| udev->state == USB_STATE_NOTATTACHED) {