USB: EHCI: suppress unwanted error messages

This patch (as1096) fixes an annoying problem: When a full-speed or
low-speed device is plugged into an EHCI controller, it fails to
enumerate at high speed and then is handed over to the companion
controller.  But usbcore logs a misleading and unwanted error message
when the high-speed enumeration fails.

The patch adds a new HCD method, port_handed_over, which asks whether
a port has been handed over to a companion controller.  If it has, the
error message is suppressed.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 1e4b81e9eb50..a0bf5df6cb6f 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -213,6 +213,8 @@ struct hc_driver {
 
                 /* force handover of high-speed port to full-speed companion */
         void    (*relinquish_port)(struct usb_hcd *, int);
+                /* has a port been handed over to a companion? */
+        int     (*port_handed_over)(struct usb_hcd *, int);
 };
 
 extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1a3d2879bc1d..8eb4da332f56 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2753,7 +2753,11 @@ loop:
                 if ((status == -ENOTCONN) || (status == -ENOTSUPP))
                         break;
         }
-        dev_err(hub_dev, "unable to enumerate USB device on port %d\n", port1);
+        if (hub->hdev->parent ||
+                        !hcd->driver->port_handed_over ||
+                        !(hcd->driver->port_handed_over)(hcd, port1))
+                dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
+                                port1);
  
 done:
         hub_port_disable(hub, port1, 1);