2 files changed, 84 insertions, 6 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 5c31d2c2f95a..b5bd6bd8fd12 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2610,6 +2610,57 @@ static int check_port_resume_type(struct usb_device *udev,
         return status;
 }
 
+static bool usb_device_supports_ltm(struct usb_device *udev)
+{
+        if (udev->speed != USB_SPEED_SUPER || !udev->bos || !udev->bos->ss_cap)
+                return false;
+        return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT;
+}
+
+int usb_disable_ltm(struct usb_device *udev)
+{
+        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+        /* Check if the roothub and device supports LTM. */
+        if (!usb_device_supports_ltm(hcd->self.root_hub) ||
+                        !usb_device_supports_ltm(udev))
+                return 0;
+
+        /* Clear Feature LTM Enable can only be sent if the device is
+         * configured.
+         */
+        if (!udev->actconfig)
+                return 0;
+
+        return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+                        USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
+                        USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
+                        USB_CTRL_SET_TIMEOUT);
+}
+EXPORT_SYMBOL_GPL(usb_disable_ltm);
+
+void usb_enable_ltm(struct usb_device *udev)
+{
+        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+        /* Check if the roothub and device supports LTM. */
+        if (!usb_device_supports_ltm(hcd->self.root_hub) ||
+                        !usb_device_supports_ltm(udev))
+                return;
+
+        /* Set Feature LTM Enable can only be sent if the device is
+         * configured.
+         */
+        if (!udev->actconfig)
+                return;
+
+        usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+                        USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
+                        USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
+                        USB_CTRL_SET_TIMEOUT);
+}
+EXPORT_SYMBOL_GPL(usb_enable_ltm);
+
 #ifdef  CONFIG_USB_SUSPEND
 
 /*
@@ -2705,6 +2756,11 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
         if (udev->usb2_hw_lpm_enabled == 1)
                 usb_set_usb2_hardware_lpm(udev, 0);
 
+        if (usb_disable_ltm(udev)) {
+                dev_err(&udev->dev, "%s Failed to disable LTM before suspend\n.",
+                                __func__);
+                return -ENOMEM;
+        }
         if (usb_unlocked_disable_lpm(udev)) {
                 dev_err(&udev->dev, "%s Failed to disable LPM before suspend\n.",
                                 __func__);
@@ -2734,7 +2790,8 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
                 if (udev->usb2_hw_lpm_capable == 1)
                         usb_set_usb2_hardware_lpm(udev, 1);
 
-                /* Try to enable USB3 LPM again */
+                /* Try to enable USB3 LTM and LPM again */
+                usb_enable_ltm(udev);
                 usb_unlocked_enable_lpm(udev);
 
                 /* System sleep transitions should never fail */
@@ -2935,7 +2992,8 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
                 if (udev->usb2_hw_lpm_capable == 1)
                         usb_set_usb2_hardware_lpm(udev, 1);
 
-                /* Try to enable USB3 LPM */
+                /* Try to enable USB3 LTM and LPM */
+                usb_enable_ltm(udev);
                 usb_unlocked_enable_lpm(udev);
         }
 
@@ -3488,6 +3546,15 @@ EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
 
 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
+
+int usb_disable_ltm(struct usb_device *udev)
+{
+        return 0;
+}
+EXPORT_SYMBOL_GPL(usb_disable_ltm);
+
+void usb_enable_ltm(struct usb_device *udev) { }
+EXPORT_SYMBOL_GPL(usb_enable_ltm);
 #endif
 
 
@@ -4673,15 +4740,22 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
         }
         parent_hub = hdev_to_hub(parent_hdev);
 
-        /* Disable LPM while we reset the device and reinstall the alt settings.
-         * Device-initiated LPM settings, and system exit latency settings are
-         * cleared when the device is reset, so we have to set them up again.
+        /* Disable LPM and LTM while we reset the device and reinstall the alt
+         * settings.  Device-initiated LPM settings, and system exit latency
+         * settings are cleared when the device is reset, so we have to set
+         * them up again.
          */
         ret = usb_unlocked_disable_lpm(udev);
         if (ret) {
                 dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
                 goto re_enumerate;
         }
+        ret = usb_disable_ltm(udev);
+        if (ret) {
+                dev_err(&udev->dev, "%s Failed to disable LTM\n.",
+                                __func__);
+                goto re_enumerate;
+        }
 
         set_bit(port1, parent_hub->busy_bits);
         for (i = 0; i < SET_CONFIG_TRIES; ++i) {
@@ -4769,8 +4843,9 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
         }
 
 done:
-        /* Now that the alt settings are re-installed, enable LPM. */
+        /* Now that the alt settings are re-installed, enable LTM and LPM. */
         usb_unlocked_enable_lpm(udev);
+        usb_enable_ltm(udev);
         return 0;
  
 re_enumerate:
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index c0877b7f505a..0ab7da2283e3 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1175,6 +1175,7 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0)
                         dev->actconfig->interface[i] = NULL;
                 }
                 usb_unlocked_disable_lpm(dev);
+                usb_disable_ltm(dev);
                 dev->actconfig = NULL;
                 if (dev->state == USB_STATE_CONFIGURED)
                         usb_set_device_state(dev, USB_STATE_ADDRESS);
@@ -1879,6 +1880,8 @@ free_interfaces:
 
         /* Now that the interfaces are installed, re-enable LPM. */
         usb_unlocked_enable_lpm(dev);
+        /* Enable LTM if it was turned off by usb_disable_device. */
+        usb_enable_ltm(dev);
 
         /* Now that all the interfaces are set up, register them
          * to trigger binding of drivers to interfaces.  probe()