[PATCH 3.18 006/144] xhci: Dont print a warning when setting link state for disabled ports

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

commit 1208d8a84fdcae6b395c57911cdf907450d30e70 upstream.

When disabling a USB3 port the hub driver will set the port link state to
U3 to prevent "ejected" or "safely removed" devices that are still
physically connected from immediately re-enumerating.

If the device was really unplugged, then error messages were printed
as the hub tries to set the U3 link state for a port that is no longer
enabled.

xhci-hcd ee000000.usb: Cannot set link state.
usb usb8-port1: cannot disable (err = -32)

Don't print error message in xhci-hub if hub tries to set port link state
for a disabled port. Return -ENODEV instead which also silences hub driver.

Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Ross Zwisler <zwisler@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/host/xhci-hub.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -926,17 +926,17 @@ int xhci_hub_control(struct usb_hcd *hcd
 				temp = readl(port_array[wIndex]);
 				break;
 			}
-
-			/* Software should not attempt to set
-			 * port link state above '3' (U3) and the port
-			 * must be enabled.
-			 */
-			if ((temp & PORT_PE) == 0 ||
-				(link_state > USB_SS_PORT_LS_U3)) {
-				xhci_warn(xhci, "Cannot set link state.\n");
+			/* Port must be enabled */
+			if (!(temp & PORT_PE)) {
+				retval = -ENODEV;
+				break;
+			}
+			/* Can't set port link state above '3' (U3) */
+			if (link_state > USB_SS_PORT_LS_U3) {
+				xhci_warn(xhci, "Cannot set port %d link state %d\n",
+					 wIndex, link_state);
 				goto error;
 			}
-
 			if (link_state == USB_SS_PORT_LS_U3) {
 				slot_id = xhci_find_slot_id_by_port(hcd, xhci,
 						wIndex + 1);