Merge remote-tracking branch 'lsk/v3.10/topic/gator' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / drivers / usb / core / hub.c

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 46efdca96952705541f2decafb654c0c437de050..63c217053668ae79f3dce71144678287abec9471 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -887,6 +887,25 @@ static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
        if (!hub_is_superspeed(hub->hdev))
                return -EINVAL;
 
+       ret = hub_port_status(hub, port1, &portstatus, &portchange);
+       if (ret < 0)
+               return ret;
+
+       /*
+        * USB controller Advanced Micro Devices, Inc. [AMD] FCH USB XHCI
+        * Controller [1022:7814] will have spurious result making the following
+        * usb 3.0 device hotplugging route to the 2.0 root hub and recognized
+        * as high-speed device if we set the usb 3.0 port link state to
+        * Disabled. Since it's already in USB_SS_PORT_LS_RX_DETECT state, we
+        * check the state here to avoid the bug.
+        */
+       if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
+                               USB_SS_PORT_LS_RX_DETECT) {
+               dev_dbg(&hub->ports[port1 - 1]->dev,
+                        "Not disabling port; link state is RxDetect\n");
+               return ret;
+       }
+
        ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
        if (ret)
                return ret;