[PATCH 3.18 20/27] usb: core: handle hub C_PORT_OVER_CURRENT condition

[Greg Kroah-Hartman]

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

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

From: Bin Liu <b-liu@xxxxxx>

commit 249a32b7eeb3edb6897dd38f89651a62163ac4ed upstream.

Based on USB2.0 Spec Section 11.12.5,

  "If a hub has per-port power switching and per-port current limiting,
  an over-current on one port may still cause the power on another port
  to fall below specific minimums. In this case, the affected port is
  placed in the Power-Off state and C_PORT_OVER_CURRENT is set for the
  port, but PORT_OVER_CURRENT is not set."

so let's check C_PORT_OVER_CURRENT too for over current condition.

Fixes: 08d1dec6f405 ("usb:hub set hub->change_bits when over-current happens")
Cc: <stable@xxxxxxxxxxxxxxx>
Tested-by: Alessandro Antenucci <antenucci@xxxxxxx>
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/core/hub.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1151,10 +1151,14 @@ static void hub_activate(struct usb_hub
 
 		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
 			/* Tell hub_wq to disconnect the device or
-			 * check for a new connection
+			 * check for a new connection or over current condition.
+			 * Based on USB2.0 Spec Section 11.12.5,
+			 * C_PORT_OVER_CURRENT could be set while
+			 * PORT_OVER_CURRENT is not. So check for any of them.
 			 */
 			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
-			    (portstatus & USB_PORT_STAT_OVERCURRENT))
+			    (portstatus & USB_PORT_STAT_OVERCURRENT) ||
+			    (portchange & USB_PORT_STAT_C_OVERCURRENT))
 				set_bit(port1, hub->change_bits);
 
 		} else if (portstatus & USB_PORT_STAT_ENABLE) {