1 files changed, 38 insertions, 7 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 92dde941fdbe..06cec635e703 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1112,16 +1112,13 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
                         /*
                          * USB3 protocol ports will automatically transition
                          * to Enabled state when detect an USB3.0 device attach.
-                         * Do not disable USB3 protocol ports.
+                         * Do not disable USB3 protocol ports, just pretend
+                         * power was lost
                          */
-                        if (!hub_is_superspeed(hdev)) {
+                        portstatus &= ~USB_PORT_STAT_ENABLE;
+                        if (!hub_is_superspeed(hdev))
                                 usb_clear_port_feature(hdev, port1,
                                                    USB_PORT_FEAT_ENABLE);
-                                portstatus &= ~USB_PORT_STAT_ENABLE;
-                        } else {
-                                /* Pretend that power was lost for USB3 devs */
-                                portstatus &= ~USB_PORT_STAT_ENABLE;
-                        }
                 }
 
                 /* Clear status-change flags; we'll debounce later */
@@ -3958,6 +3955,32 @@ static int hub_set_address(struct usb_device *udev, int devnum)
         return retval;
 }
 
+/*
+ * There are reports of USB 3.0 devices that say they support USB 2.0 Link PM
+ * when they're plugged into a USB 2.0 port, but they don't work when LPM is
+ * enabled.
+ *
+ * Only enable USB 2.0 Link PM if the port is internal (hardwired), or the
+ * device says it supports the new USB 2.0 Link PM errata by setting the BESL
+ * support bit in the BOS descriptor.
+ */
+static void hub_set_initial_usb2_lpm_policy(struct usb_device *udev)
+{
+        int connect_type;
+
+        if (!udev->usb2_hw_lpm_capable)
+                return;
+
+        connect_type = usb_get_hub_port_connect_type(udev->parent,
+                        udev->portnum);
+
+        if ((udev->bos->ext_cap->bmAttributes & USB_BESL_SUPPORT) ||
+                        connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
+                udev->usb2_hw_lpm_allowed = 1;
+                usb_set_usb2_hardware_lpm(udev, 1);
+        }
+}
+
 /* Reset device, (re)assign address, get device descriptor.
  * Device connection must be stable, no more debouncing needed.
  * Returns device in USB_STATE_ADDRESS, except on error.
@@ -4251,6 +4274,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
         /* notify HCD that we have a device connected and addressed */
         if (hcd->driver->update_device)
                 hcd->driver->update_device(hcd, udev);
+        hub_set_initial_usb2_lpm_policy(udev);
 fail:
         if (retval) {
                 hub_port_disable(hub, port1, 0);
@@ -5095,6 +5119,12 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
         }
         parent_hub = usb_hub_to_struct_hub(parent_hdev);
 
+        /* Disable USB2 hardware LPM.
+         * It will be re-enabled by the enumeration process.
+         */
+        if (udev->usb2_hw_lpm_enabled == 1)
+                usb_set_usb2_hardware_lpm(udev, 0);
+
         bos = udev->bos;
         udev->bos = NULL;
 
@@ -5202,6 +5232,7 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
 
 done:
         /* Now that the alt settings are re-installed, enable LTM and LPM. */
+        usb_set_usb2_hardware_lpm(udev, 1);
         usb_unlocked_enable_lpm(udev);
         usb_enable_ltm(udev);
         usb_release_bos_descriptor(udev);